Potency of an inactivated influenza vaccine prepared from A/duck/Hokkaido/162/2013 (H2N1) against a challenge with A/swine/Missouri/2124514/2006 (H2N3) in mice
Identifieur interne : 000A18 ( Pmc/Corpus ); précédent : 000A17; suivant : 000A19Potency of an inactivated influenza vaccine prepared from A/duck/Hokkaido/162/2013 (H2N1) against a challenge with A/swine/Missouri/2124514/2006 (H2N3) in mice
Auteurs : Mizuho Suzuki ; Masatoshi Okamatsu ; Takahiro Hiono ; Keita Matsuno ; Yoshihiro SakodaSource :
- The Journal of Veterinary Medical Science [ 0916-7250 ] ; 2017.
Abstract
H2N2 influenza virus caused a pandemic starting in 1957 but has not been detected in humans since 1968. Thus, most people are immunologically naive to viruses of the H2 subtype. In contrast, H2 influenza viruses are continually isolated from wild birds, and H2N3 viruses were isolated from pigs in 2006. H2 influenza viruses could cause a pandemic if re-introduced into humans. In the present study, a vaccine against H2 influenza was prepared as an effective control measure against a future human pandemic. A/duck/Hokkaido/162/2013 (H2N1), which showed broad antigenic cross-reactivity, was selected from the candidate H2 influenza viruses recently isolated from wild birds in Asian countries. Sufficient neutralizing antibodies against homologous and heterologous viruses were induced in mice after two subcutaneous injections of the inactivated whole virus particle vaccine. The inactivated vaccine induced protective immunity sufficient to reduce the impact of challenges with A/swine/Missouri/2124514/2006 (H2N3). This study demonstrates that the inactivated whole virus particle vaccine prepared from an influenza virus library would be useful against a future H2 influenza pandemic.
Url:
DOI: 10.1292/jvms.17-0312
PubMed: 28993601
PubMed Central: 5709558
Links to Exploration step
PMC:5709558Le document en format XML
<record><TEI><teiHeader><fileDesc><titleStmt><title xml:lang="en">Potency of an inactivated influenza vaccine prepared from A/duck/Hokkaido/162/2013 (H2N1) against a challenge with A/swine/Missouri/2124514/2006 (H2N3) in mice</title><author><name sortKey="Suzuki, Mizuho" sort="Suzuki, Mizuho" uniqKey="Suzuki M" first="Mizuho" last="Suzuki">Mizuho Suzuki</name><affiliation><nlm:aff>NONE</nlm:aff></affiliation></author><author><name sortKey="Okamatsu, Masatoshi" sort="Okamatsu, Masatoshi" uniqKey="Okamatsu M" first="Masatoshi" last="Okamatsu">Masatoshi Okamatsu</name><affiliation><nlm:aff>NONE</nlm:aff></affiliation></author><author><name sortKey="Hiono, Takahiro" sort="Hiono, Takahiro" uniqKey="Hiono T" first="Takahiro" last="Hiono">Takahiro Hiono</name><affiliation><nlm:aff>NONE</nlm:aff></affiliation></author><author><name sortKey="Matsuno, Keita" sort="Matsuno, Keita" uniqKey="Matsuno K" first="Keita" last="Matsuno">Keita Matsuno</name><affiliation><nlm:aff>NONE</nlm:aff></affiliation><affiliation><nlm:aff>NONE</nlm:aff></affiliation></author><author><name sortKey="Sakoda, Yoshihiro" sort="Sakoda, Yoshihiro" uniqKey="Sakoda Y" first="Yoshihiro" last="Sakoda">Yoshihiro Sakoda</name><affiliation><nlm:aff>NONE</nlm:aff></affiliation><affiliation><nlm:aff>NONE</nlm:aff></affiliation></author></titleStmt><publicationStmt><idno type="wicri:source">PMC</idno><idno type="pmid">28993601</idno><idno type="pmc">5709558</idno><idno type="url">http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5709558</idno><idno type="RBID">PMC:5709558</idno><idno type="doi">10.1292/jvms.17-0312</idno><date when="2017">2017</date><idno type="wicri:Area/Pmc/Corpus">000A18</idno><idno type="wicri:explorRef" wicri:stream="Pmc" wicri:step="Corpus" wicri:corpus="PMC">000A18</idno></publicationStmt><sourceDesc><biblStruct><analytic><title xml:lang="en" level="a" type="main">Potency of an inactivated influenza vaccine prepared from A/duck/Hokkaido/162/2013 (H2N1) against a challenge with A/swine/Missouri/2124514/2006 (H2N3) in mice</title><author><name sortKey="Suzuki, Mizuho" sort="Suzuki, Mizuho" uniqKey="Suzuki M" first="Mizuho" last="Suzuki">Mizuho Suzuki</name><affiliation><nlm:aff>NONE</nlm:aff></affiliation></author><author><name sortKey="Okamatsu, Masatoshi" sort="Okamatsu, Masatoshi" uniqKey="Okamatsu M" first="Masatoshi" last="Okamatsu">Masatoshi Okamatsu</name><affiliation><nlm:aff>NONE</nlm:aff></affiliation></author><author><name sortKey="Hiono, Takahiro" sort="Hiono, Takahiro" uniqKey="Hiono T" first="Takahiro" last="Hiono">Takahiro Hiono</name><affiliation><nlm:aff>NONE</nlm:aff></affiliation></author><author><name sortKey="Matsuno, Keita" sort="Matsuno, Keita" uniqKey="Matsuno K" first="Keita" last="Matsuno">Keita Matsuno</name><affiliation><nlm:aff>NONE</nlm:aff></affiliation><affiliation><nlm:aff>NONE</nlm:aff></affiliation></author><author><name sortKey="Sakoda, Yoshihiro" sort="Sakoda, Yoshihiro" uniqKey="Sakoda Y" first="Yoshihiro" last="Sakoda">Yoshihiro Sakoda</name><affiliation><nlm:aff>NONE</nlm:aff></affiliation><affiliation><nlm:aff>NONE</nlm:aff></affiliation></author></analytic><series><title level="j">The Journal of Veterinary Medical Science</title><idno type="ISSN">0916-7250</idno><idno type="eISSN">1347-7439</idno><imprint><date when="2017">2017</date></imprint></series></biblStruct></sourceDesc></fileDesc><profileDesc><textClass></textClass></profileDesc></teiHeader><front><div type="abstract" xml:lang="en"><p>H2N2 influenza virus caused a pandemic starting in 1957 but has not been detected in humans since 1968. Thus, most people are immunologically naive to viruses of the H2 subtype. In contrast, H2 influenza viruses are continually
isolated from wild birds, and H2N3 viruses were isolated from pigs in 2006. H2 influenza viruses could cause a pandemic if re-introduced into humans. In the present study, a vaccine against H2 influenza was prepared as an
effective control measure against a future human pandemic. A/duck/Hokkaido/162/2013 (H2N1), which showed broad antigenic cross-reactivity, was selected from the candidate H2 influenza viruses recently isolated from wild birds in
Asian countries. Sufficient neutralizing antibodies against homologous and heterologous viruses were induced in mice after two subcutaneous injections of the inactivated whole virus particle vaccine. The inactivated vaccine
induced protective immunity sufficient to reduce the impact of challenges with A/swine/Missouri/2124514/2006 (H2N3). This study demonstrates that the inactivated whole virus particle vaccine prepared from an influenza virus
library would be useful against a future H2 influenza pandemic.</p></div></front><back><div1 type="bibliography"><listBibl><biblStruct><analytic><author><name sortKey="Arikata, M" uniqKey="Arikata M">M. Arikata</name></author><author><name sortKey="Itoh, Y" uniqKey="Itoh Y">Y. Itoh</name></author><author><name sortKey="Okamatsu, M" uniqKey="Okamatsu M">M. Okamatsu</name></author><author><name sortKey="Maeda, T" uniqKey="Maeda T">T. Maeda</name></author><author><name sortKey="Shiina, T" uniqKey="Shiina T">T. Shiina</name></author><author><name sortKey="Tanaka, K" uniqKey="Tanaka K">K. Tanaka</name></author><author><name sortKey="Suzuki, S" uniqKey="Suzuki S">S. Suzuki</name></author><author><name sortKey="Nakayama, M" uniqKey="Nakayama M">M. Nakayama</name></author><author><name sortKey="Sakoda, Y" uniqKey="Sakoda Y">Y. Sakoda</name></author><author><name sortKey="Ishigaki, H" uniqKey="Ishigaki H">H. Ishigaki</name></author><author><name sortKey="Takada, A" uniqKey="Takada A">A. Takada</name></author><author><name sortKey="Ishida, H" uniqKey="Ishida H">H. Ishida</name></author><author><name sortKey="Soda, K" uniqKey="Soda K">K. Soda</name></author><author><name sortKey="Pham, V L" uniqKey="Pham V">V. L. Pham</name></author><author><name sortKey="Tsuchiya, H" uniqKey="Tsuchiya H">H. Tsuchiya</name></author><author><name sortKey="Nakamura, S" uniqKey="Nakamura S">S. Nakamura</name></author><author><name sortKey="Torii, R" uniqKey="Torii R">R. Torii</name></author><author><name sortKey="Shimizu, T" uniqKey="Shimizu T">T. Shimizu</name></author><author><name sortKey="Inoko, H" uniqKey="Inoko H">H. Inoko</name></author><author><name sortKey="Ohkubo, I" uniqKey="Ohkubo I">I. Ohkubo</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author><author><name sortKey="Ogasawara, K" uniqKey="Ogasawara K">K. Ogasawara</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Chen, G L" uniqKey="Chen G">G. L. Chen</name></author><author><name sortKey="Lamirande, E W" uniqKey="Lamirande E">E. W. Lamirande</name></author><author><name sortKey="Jin, H" uniqKey="Jin H">H. Jin</name></author><author><name sortKey="Kemble, G" uniqKey="Kemble G">G. Kemble</name></author><author><name sortKey="Subbarao, K" uniqKey="Subbarao K">K. Subbarao</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Chen, G L" uniqKey="Chen G">G. L. Chen</name></author><author><name sortKey="Lamirande, E W" uniqKey="Lamirande E">E. W. Lamirande</name></author><author><name sortKey="Cheng, X" uniqKey="Cheng X">X. Cheng</name></author><author><name sortKey="Torres Velez, F" uniqKey="Torres Velez F">F. Torres-Velez</name></author><author><name sortKey="Orandle, M" uniqKey="Orandle M">M. Orandle</name></author><author><name sortKey="Jin, H" uniqKey="Jin H">H. Jin</name></author><author><name sortKey="Kemble, G" uniqKey="Kemble G">G. Kemble</name></author><author><name sortKey="Subbarao, K" uniqKey="Subbarao K">K. Subbarao</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Chu, D H" uniqKey="Chu D">D. H. Chu</name></author><author><name sortKey="Sakoda, Y" uniqKey="Sakoda Y">Y. Sakoda</name></author><author><name sortKey="Nishi, T" uniqKey="Nishi T">T. Nishi</name></author><author><name sortKey="Hiono, T" uniqKey="Hiono T">T. Hiono</name></author><author><name sortKey="Shichinohe, S" uniqKey="Shichinohe S">S. Shichinohe</name></author><author><name sortKey="Okamatsu, M" uniqKey="Okamatsu M">M. Okamatsu</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Govorkova, E A" uniqKey="Govorkova E">E. A. Govorkova</name></author><author><name sortKey="Smirnov Yua" uniqKey="Smirnov Yua">Smirnov YuA</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Hall, J S" uniqKey="Hall J">J. S. Hall</name></author><author><name sortKey="Hallgrimsson, G T" uniqKey="Hallgrimsson G">G. T. Hallgrimsson</name></author><author><name sortKey="Suwannanarn, K" uniqKey="Suwannanarn K">K. Suwannanarn</name></author><author><name sortKey="Sreevatsen, S" uniqKey="Sreevatsen S">S. Sreevatsen</name></author><author><name sortKey="Ip, H S" uniqKey="Ip H">H. S. Ip</name></author><author><name sortKey="Magnusdottir, E" uniqKey="Magnusdottir E">E. Magnusdottir</name></author><author><name sortKey="Teslaa, J L" uniqKey="Teslaa J">J. L. TeSlaa</name></author><author><name sortKey="Nashold, S W" uniqKey="Nashold S">S. W. Nashold</name></author><author><name sortKey="Dusek, R J" uniqKey="Dusek R">R. J. Dusek</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Hiono, T" uniqKey="Hiono T">T. Hiono</name></author><author><name sortKey="Ohkawara, A" uniqKey="Ohkawara A">A. Ohkawara</name></author><author><name sortKey="Ogasawara, K" uniqKey="Ogasawara K">K. Ogasawara</name></author><author><name sortKey="Okamatsu, M" uniqKey="Okamatsu M">M. Okamatsu</name></author><author><name sortKey="Tamura, T" uniqKey="Tamura T">T. Tamura</name></author><author><name sortKey="Chu, D H" uniqKey="Chu D">D. H. Chu</name></author><author><name sortKey="Suzuki, M" uniqKey="Suzuki M">M. Suzuki</name></author><author><name sortKey="Kuribayashi, S" uniqKey="Kuribayashi S">S. Kuribayashi</name></author><author><name sortKey="Shichinohe, S" uniqKey="Shichinohe S">S. Shichinohe</name></author><author><name sortKey="Takada, A" uniqKey="Takada A">A. Takada</name></author><author><name sortKey="Ogawa, H" uniqKey="Ogawa H">H. Ogawa</name></author><author><name sortKey="Yoshida, R" uniqKey="Yoshida R">R. Yoshida</name></author><author><name sortKey="Miyamoto, H" uniqKey="Miyamoto H">H. Miyamoto</name></author><author><name sortKey="Nao, N" uniqKey="Nao N">N. Nao</name></author><author><name sortKey="Furuyama, W" uniqKey="Furuyama W">W. Furuyama</name></author><author><name sortKey="Maruyama, J" uniqKey="Maruyama J">J. Maruyama</name></author><author><name sortKey="Eguchi, N" uniqKey="Eguchi N">N. Eguchi</name></author><author><name sortKey="Ulziibat, G" uniqKey="Ulziibat G">G. Ulziibat</name></author><author><name sortKey="Enkhbold, B" uniqKey="Enkhbold B">B. Enkhbold</name></author><author><name sortKey="Shatar, M" uniqKey="Shatar M">M. Shatar</name></author><author><name sortKey="Jargalsaikhan, T" uniqKey="Jargalsaikhan T">T. Jargalsaikhan</name></author><author><name sortKey="Byambadorj, S" uniqKey="Byambadorj S">S. Byambadorj</name></author><author><name sortKey="Damdinjav, B" uniqKey="Damdinjav B">B. Damdinjav</name></author><author><name sortKey="Sakoda, Y" uniqKey="Sakoda Y">Y. Sakoda</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Hoffmann, E" uniqKey="Hoffmann E">E. Hoffmann</name></author><author><name sortKey="Stech, J" uniqKey="Stech J">J. Stech</name></author><author><name sortKey="Guan, Y" uniqKey="Guan Y">Y. Guan</name></author><author><name sortKey="Webster, R G" uniqKey="Webster R">R. G. Webster</name></author><author><name sortKey="Perez, D R" uniqKey="Perez D">D. R. Perez</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Hovden, A O" uniqKey="Hovden A">A. O. Hovden</name></author><author><name sortKey="Brokstad, K A" uniqKey="Brokstad K">K. A. Brokstad</name></author><author><name sortKey="Major, D" uniqKey="Major D">D. Major</name></author><author><name sortKey="Wood, J" uniqKey="Wood J">J. Wood</name></author><author><name sortKey="Haaheim, L R" uniqKey="Haaheim L">L. R. Haaheim</name></author><author><name sortKey="Cox, R J" uniqKey="Cox R">R. J. Cox</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Ito, T" uniqKey="Ito T">T. Ito</name></author><author><name sortKey="Okazaki, K" uniqKey="Okazaki K">K. Okazaki</name></author><author><name sortKey="Kawaoka, Y" uniqKey="Kawaoka Y">Y. Kawaoka</name></author><author><name sortKey="Takada, A" uniqKey="Takada A">A. Takada</name></author><author><name sortKey="Webster, R G" uniqKey="Webster R">R. G. Webster</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Itoh, Y" uniqKey="Itoh Y">Y. Itoh</name></author><author><name sortKey="Ozaki, H" uniqKey="Ozaki H">H. Ozaki</name></author><author><name sortKey="Ishigaki, H" uniqKey="Ishigaki H">H. Ishigaki</name></author><author><name sortKey="Sakoda, Y" uniqKey="Sakoda Y">Y. Sakoda</name></author><author><name sortKey="Nagata, T" uniqKey="Nagata T">T. Nagata</name></author><author><name sortKey="Soda, K" uniqKey="Soda K">K. Soda</name></author><author><name sortKey="Isoda, N" uniqKey="Isoda N">N. Isoda</name></author><author><name sortKey="Miyake, T" uniqKey="Miyake T">T. Miyake</name></author><author><name sortKey="Ishida, H" uniqKey="Ishida H">H. Ishida</name></author><author><name sortKey="Okamoto, K" uniqKey="Okamoto K">K. Okamoto</name></author><author><name sortKey="Nakayama, M" uniqKey="Nakayama M">M. Nakayama</name></author><author><name sortKey="Tsuchiya, H" uniqKey="Tsuchiya H">H. Tsuchiya</name></author><author><name sortKey="Torii, R" uniqKey="Torii R">R. Torii</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author><author><name sortKey="Ogasawara, K" uniqKey="Ogasawara K">K. Ogasawara</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Itoh, Y" uniqKey="Itoh Y">Y. Itoh</name></author><author><name sortKey="Ozaki, H" uniqKey="Ozaki H">H. Ozaki</name></author><author><name sortKey="Tsuchiya, H" uniqKey="Tsuchiya H">H. Tsuchiya</name></author><author><name sortKey="Okamoto, K" uniqKey="Okamoto K">K. Okamoto</name></author><author><name sortKey="Torii, R" uniqKey="Torii R">R. Torii</name></author><author><name sortKey="Sakoda, Y" uniqKey="Sakoda Y">Y. Sakoda</name></author><author><name sortKey="Kawaoka, Y" uniqKey="Kawaoka Y">Y. Kawaoka</name></author><author><name sortKey="Ogasawara, K" uniqKey="Ogasawara K">K. Ogasawara</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Jones, J C" uniqKey="Jones J">J. C. Jones</name></author><author><name sortKey="Baranovich, T" uniqKey="Baranovich T">T. Baranovich</name></author><author><name sortKey="Marathe, B M" uniqKey="Marathe B">B. M. Marathe</name></author><author><name sortKey="Danner, A F" uniqKey="Danner A">A. F. Danner</name></author><author><name sortKey="Seiler, J P" uniqKey="Seiler J">J. P. Seiler</name></author><author><name sortKey="Franks, J" uniqKey="Franks J">J. Franks</name></author><author><name sortKey="Govorkova, E A" uniqKey="Govorkova E">E. A. Govorkova</name></author><author><name sortKey="Krauss, S" uniqKey="Krauss S">S. Krauss</name></author><author><name sortKey="Webster, R G" uniqKey="Webster R">R. G. Webster</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Kaverin, N V" uniqKey="Kaverin N">N. V. Kaverin</name></author><author><name sortKey="Smirnov, Y A" uniqKey="Smirnov Y">Y. A. Smirnov</name></author><author><name sortKey="Govorkova, E A" uniqKey="Govorkova E">E. A. Govorkova</name></author><author><name sortKey="Rudneva, I A" uniqKey="Rudneva I">I. A. Rudneva</name></author><author><name sortKey="Gitelman, A K" uniqKey="Gitelman A">A. K. Gitelman</name></author><author><name sortKey="Lipatov, A S" uniqKey="Lipatov A">A. S. Lipatov</name></author><author><name sortKey="Varich, N L" uniqKey="Varich N">N. L. Varich</name></author><author><name sortKey="Yamnikova, S S" uniqKey="Yamnikova S">S. S. Yamnikova</name></author><author><name sortKey="Makarova, N V" uniqKey="Makarova N">N. V. Makarova</name></author><author><name sortKey="Webster, R G" uniqKey="Webster R">R. G. Webster</name></author><author><name sortKey="Lvov, D K" uniqKey="Lvov D">D. K. Lvov</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author><author><name sortKey="Brown, L E" uniqKey="Brown L">L. E. Brown</name></author><author><name sortKey="Webster, R G" uniqKey="Webster R">R. G. Webster</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Kishida, N" uniqKey="Kishida N">N. Kishida</name></author><author><name sortKey="Sakoda, Y" uniqKey="Sakoda Y">Y. Sakoda</name></author><author><name sortKey="Shiromoto, M" uniqKey="Shiromoto M">M. Shiromoto</name></author><author><name sortKey="Bai, G R" uniqKey="Bai G">G. R. Bai</name></author><author><name sortKey="Isoda, N" uniqKey="Isoda N">N. Isoda</name></author><author><name sortKey="Takada, A" uniqKey="Takada A">A. Takada</name></author><author><name sortKey="Laver, G" uniqKey="Laver G">G. Laver</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Krauss, S" uniqKey="Krauss S">S. Krauss</name></author><author><name sortKey="Obert, C A" uniqKey="Obert C">C. A. Obert</name></author><author><name sortKey="Franks, J" uniqKey="Franks J">J. Franks</name></author><author><name sortKey="Walker, D" uniqKey="Walker D">D. Walker</name></author><author><name sortKey="Jones, K" uniqKey="Jones K">K. Jones</name></author><author><name sortKey="Seiler, P" uniqKey="Seiler P">P. Seiler</name></author><author><name sortKey="Niles, L" uniqKey="Niles L">L. Niles</name></author><author><name sortKey="Pryor, S P" uniqKey="Pryor S">S. P. Pryor</name></author><author><name sortKey="Obenauer, J C" uniqKey="Obenauer J">J. C. Obenauer</name></author><author><name sortKey="Naeve, C W" uniqKey="Naeve C">C. W. Naeve</name></author><author><name sortKey="Widjaja, L" uniqKey="Widjaja L">L. Widjaja</name></author><author><name sortKey="Webby, R J" uniqKey="Webby R">R. J. Webby</name></author><author><name sortKey="Webster, R G" uniqKey="Webster R">R. G. Webster</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Lenny, B J" uniqKey="Lenny B">B. J. Lenny</name></author><author><name sortKey="Sonnberg, S" uniqKey="Sonnberg S">S. Sonnberg</name></author><author><name sortKey="Danner, A F" uniqKey="Danner A">A. F. Danner</name></author><author><name sortKey="Friedman, K" uniqKey="Friedman K">K. Friedman</name></author><author><name sortKey="Webby, R J" uniqKey="Webby R">R. J. Webby</name></author><author><name sortKey="Webster, R G" uniqKey="Webster R">R. G. Webster</name></author><author><name sortKey="Jones, J C" uniqKey="Jones J">J. C. Jones</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Ma, W" uniqKey="Ma W">W. Ma</name></author><author><name sortKey="Vincent, A L" uniqKey="Vincent A">A. L. Vincent</name></author><author><name sortKey="Gramer, M R" uniqKey="Gramer M">M. R. Gramer</name></author><author><name sortKey="Brockwell, C B" uniqKey="Brockwell C">C. B. Brockwell</name></author><author><name sortKey="Lager, K M" uniqKey="Lager K">K. M. Lager</name></author><author><name sortKey="Janke, B H" uniqKey="Janke B">B. H. Janke</name></author><author><name sortKey="Gauger, P C" uniqKey="Gauger P">P. C. Gauger</name></author><author><name sortKey="Patnayak, D P" uniqKey="Patnayak D">D. P. Patnayak</name></author><author><name sortKey="Webby, R J" uniqKey="Webby R">R. J. Webby</name></author><author><name sortKey="Richt, J A" uniqKey="Richt J">J. A. Richt</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Nabel, G J" uniqKey="Nabel G">G. J. Nabel</name></author><author><name sortKey="Wei, C J" uniqKey="Wei C">C. J. Wei</name></author><author><name sortKey="Ledgerwood, J E" uniqKey="Ledgerwood J">J. E. Ledgerwood</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Nishi, T" uniqKey="Nishi T">T. Nishi</name></author><author><name sortKey="Sakoda, Y" uniqKey="Sakoda Y">Y. Sakoda</name></author><author><name sortKey="Okamatsu, M" uniqKey="Okamatsu M">M. Okamatsu</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Nomura, N" uniqKey="Nomura N">N. Nomura</name></author><author><name sortKey="Sakoda, Y" uniqKey="Sakoda Y">Y. Sakoda</name></author><author><name sortKey="Soda, K" uniqKey="Soda K">K. Soda</name></author><author><name sortKey="Okamatsu, M" uniqKey="Okamatsu M">M. Okamatsu</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Okamatsu, M" uniqKey="Okamatsu M">M. Okamatsu</name></author><author><name sortKey="Sakoda, Y" uniqKey="Sakoda Y">Y. Sakoda</name></author><author><name sortKey="Hiono, T" uniqKey="Hiono T">T. Hiono</name></author><author><name sortKey="Yamamoto, N" uniqKey="Yamamoto N">N. Yamamoto</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Piaggio, A J" uniqKey="Piaggio A">A. J. Piaggio</name></author><author><name sortKey="Shriner, S A" uniqKey="Shriner S">S. A. Shriner</name></author><author><name sortKey="Vandalen, K K" uniqKey="Vandalen K">K. K. VanDalen</name></author><author><name sortKey="Franklin, A B" uniqKey="Franklin A">A. B. Franklin</name></author><author><name sortKey="Anderson, T D" uniqKey="Anderson T">T. D. Anderson</name></author><author><name sortKey="Kolokotronis, S O" uniqKey="Kolokotronis S">S. O. Kolokotronis</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Sakabe, S" uniqKey="Sakabe S">S. Sakabe</name></author><author><name sortKey="Sakoda, Y" uniqKey="Sakoda Y">Y. Sakoda</name></author><author><name sortKey="Haraguchi, Y" uniqKey="Haraguchi Y">Y. Haraguchi</name></author><author><name sortKey="Isoda, N" uniqKey="Isoda N">N. Isoda</name></author><author><name sortKey="Soda, K" uniqKey="Soda K">K. Soda</name></author><author><name sortKey="Takakuwa, H" uniqKey="Takakuwa H">H. Takakuwa</name></author><author><name sortKey="Saijo, K" uniqKey="Saijo K">K. Saijo</name></author><author><name sortKey="Sawata, A" uniqKey="Sawata A">A. Sawata</name></author><author><name sortKey="Kume, K" uniqKey="Kume K">K. Kume</name></author><author><name sortKey="Hagiwara, J" uniqKey="Hagiwara J">J. Hagiwara</name></author><author><name sortKey="Tuchiya, K" uniqKey="Tuchiya K">K. Tuchiya</name></author><author><name sortKey="Lin, Z" uniqKey="Lin Z">Z. Lin</name></author><author><name sortKey="Sakamoto, R" uniqKey="Sakamoto R">R. Sakamoto</name></author><author><name sortKey="Imamura, T" uniqKey="Imamura T">T. Imamura</name></author><author><name sortKey="Sasaki, T" uniqKey="Sasaki T">T. Sasaki</name></author><author><name sortKey="Kokumai, N" uniqKey="Kokumai N">N. Kokumai</name></author><author><name sortKey="Kawaoka, Y" uniqKey="Kawaoka Y">Y. Kawaoka</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Sch Fer, J R" uniqKey="Sch Fer J">J. R. Schäfer</name></author><author><name sortKey="Kawaoka, Y" uniqKey="Kawaoka Y">Y. Kawaoka</name></author><author><name sortKey="Bean, W J" uniqKey="Bean W">W. J. Bean</name></author><author><name sortKey="Suss, J" uniqKey="Suss J">J. Süss</name></author><author><name sortKey="Senne, D" uniqKey="Senne D">D. Senne</name></author><author><name sortKey="Webster, R G" uniqKey="Webster R">R. G. Webster</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Simonsen, L" uniqKey="Simonsen L">L. Simonsen</name></author><author><name sortKey="Clarke, M J" uniqKey="Clarke M">M. J. Clarke</name></author><author><name sortKey="Schonberger, L B" uniqKey="Schonberger L">L. B. Schonberger</name></author><author><name sortKey="Arden, N H" uniqKey="Arden N">N. H. Arden</name></author><author><name sortKey="Cox, N J" uniqKey="Cox N">N. J. Cox</name></author><author><name sortKey="Fukuda, K" uniqKey="Fukuda K">K. Fukuda</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Wu, H" uniqKey="Wu H">H. Wu</name></author><author><name sortKey="Peng, X" uniqKey="Peng X">X. Peng</name></author><author><name sortKey="Peng, X" uniqKey="Peng X">X. Peng</name></author><author><name sortKey="Cheng, L" uniqKey="Cheng L">L. Cheng</name></author><author><name sortKey="Wu, N" uniqKey="Wu N">N. Wu</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Yamamoto, N" uniqKey="Yamamoto N">N. Yamamoto</name></author><author><name sortKey="Sakoda, Y" uniqKey="Sakoda Y">Y. Sakoda</name></author><author><name sortKey="Motoshima, M" uniqKey="Motoshima M">M. Motoshima</name></author><author><name sortKey="Yoshino, F" uniqKey="Yoshino F">F. Yoshino</name></author><author><name sortKey="Soda, K" uniqKey="Soda K">K. Soda</name></author><author><name sortKey="Okamatsu, M" uniqKey="Okamatsu M">M. Okamatsu</name></author><author><name sortKey="Kida, H" uniqKey="Kida H">H. Kida</name></author></analytic></biblStruct></listBibl></div1></back></TEI><pmc article-type="research-article"><pmc-dir>properties open_access</pmc-dir>
<front><journal-meta><journal-id journal-id-type="nlm-ta">J Vet Med Sci</journal-id><journal-id journal-id-type="iso-abbrev">J. Vet. Med. Sci</journal-id><journal-id journal-id-type="publisher-id">JVMS</journal-id><journal-title-group><journal-title>The Journal of Veterinary Medical Science</journal-title></journal-title-group><issn pub-type="ppub">0916-7250</issn><issn pub-type="epub">1347-7439</issn><publisher><publisher-name>The Japanese Society of Veterinary Science</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="pmid">28993601</article-id><article-id pub-id-type="pmc">5709558</article-id><article-id pub-id-type="publisher-id">17-0312</article-id><article-id pub-id-type="doi">10.1292/jvms.17-0312</article-id><article-categories><subj-group subj-group-type="heading"><subject>Virology</subject><subj-group><subject>Full Paper</subject></subj-group></subj-group></article-categories><title-group><article-title>Potency of an inactivated influenza vaccine prepared from A/duck/Hokkaido/162/2013 (H2N1) against a challenge with A/swine/Missouri/2124514/2006 (H2N3) in mice</article-title></title-group><contrib-group><contrib contrib-type="author"><name><surname>SUZUKI</surname><given-names>Mizuho</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author"><name><surname>OKAMATSU</surname><given-names>Masatoshi</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author"><name><surname>HIONO</surname><given-names>Takahiro</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author"><name><surname>MATSUNO</surname><given-names>Keita</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref><xref ref-type="aff" rid="aff2"><sup>2</sup></xref></contrib><contrib contrib-type="author"><name><surname>SAKODA</surname><given-names>Yoshihiro</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref><xref ref-type="aff" rid="aff2"><sup>2</sup></xref><xref rid="cor1" ref-type="corresp"><sup>*</sup></xref></contrib><aff id="aff1"><label>1)</label>Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan</aff><aff id="aff2"><label>2)</label>Global Station for Zoonosis Control, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo 060-0818, Japan</aff></contrib-group><author-notes><corresp id="cor1"><label>*</label>Correspondence to: Sakoda, Y.: <email xlink:href="sakoda@vetmed.hokudai.ac.jp">sakoda@vetmed.hokudai.ac.jp</email></corresp></author-notes><pub-date pub-type="epub"><day>07</day><month>10</month><year>2017</year></pub-date><pub-date pub-type="ppub"><month>11</month><year>2017</year></pub-date><volume>79</volume><issue>11</issue><fpage>1815</fpage><lpage>1821</lpage><history><date date-type="received"><day>06</day><month>6</month><year>2017</year></date><date date-type="accepted"><day>02</day><month>9</month><year>2017</year></date></history><permissions><copyright-statement>©2017 The Japanese Society of Veterinary Science</copyright-statement><copyright-year>2017</copyright-year><license license-type="open-access"><license-p>This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives (by-nc-nd) License. (CC-BY-NC-ND 4.0: <ext-link ext-link-type="uri" xlink:href="https://creativecommons.org/licenses/by-nc-nd/4.0/"> https://creativecommons.org/licenses/by-nc-nd/4.0/</ext-link>)</license-p></license></permissions><abstract><p>H2N2 influenza virus caused a pandemic starting in 1957 but has not been detected in humans since 1968. Thus, most people are immunologically naive to viruses of the H2 subtype. In contrast, H2 influenza viruses are continually
isolated from wild birds, and H2N3 viruses were isolated from pigs in 2006. H2 influenza viruses could cause a pandemic if re-introduced into humans. In the present study, a vaccine against H2 influenza was prepared as an
effective control measure against a future human pandemic. A/duck/Hokkaido/162/2013 (H2N1), which showed broad antigenic cross-reactivity, was selected from the candidate H2 influenza viruses recently isolated from wild birds in
Asian countries. Sufficient neutralizing antibodies against homologous and heterologous viruses were induced in mice after two subcutaneous injections of the inactivated whole virus particle vaccine. The inactivated vaccine
induced protective immunity sufficient to reduce the impact of challenges with A/swine/Missouri/2124514/2006 (H2N3). This study demonstrates that the inactivated whole virus particle vaccine prepared from an influenza virus
library would be useful against a future H2 influenza pandemic.</p></abstract><kwd-group><kwd>antigenicity</kwd><kwd>H2 influenza</kwd><kwd>pre-pandemic</kwd><kwd>vaccine</kwd></kwd-group></article-meta></front><body><p>H2N2 influenza virus was the causative agent of an influenza pandemic known as Asian flu, which started in 1957. More than one million deaths were reported worldwide. However, H2 influenza viruses have not been detected in the human
population since 1968 in replacement of another pandemic influenza caused by H3N2 influenza viruses. In contrast, H2 avian influenza viruses have been continuously circulating in wild aquatic and sporadically isolated from domestic
birds around the world [<xref rid="r6" ref-type="bibr">6</xref>, <xref rid="r16" ref-type="bibr">16</xref>, <xref rid="r17" ref-type="bibr">17</xref>, <xref rid="r24" ref-type="bibr">24</xref>, <xref rid="r28" ref-type="bibr">28</xref>, <xref rid="r29" ref-type="bibr">29</xref>]. In addition, H2N3 influenza viruses were isolated from pigs in 2006 in Missouri, U.S.A. [<xref rid="r19" ref-type="bibr">19</xref>]. These facts suggest that avian H2 influenza
viruses may occasionally transmit to pigs and can be re-introduced into the human population in the future. Such an event could result in a pandemic because of the lack of acquired immunity against H2 influenza viruses in the current
human population [<xref rid="r27" ref-type="bibr">27</xref>]. Therefore, vaccines against H2 influenza viruses are needed to prepare for a future human pandemic [<xref rid="r20" ref-type="bibr">20</xref>].</p><p>The HA genes of H2 influenza viruses are phylogenetically divided into North American and Eurasian lineages [<xref rid="r26" ref-type="bibr">26</xref>]. The H2N2 influenza viruses that caused Asian flu belong to the Eurasian lineage
and the H2N3 influenza viruses that were isolated from pigs in 2006 belong to the North American lineage. The avian H2 influenza virus A/black duck/New Jersey/1580/1978 (H2N3) antigenically cross-reacts with H2 influenza viruses
isolated from humans and birds before 1991 [<xref rid="r5" ref-type="bibr">5</xref>, <xref rid="r14" ref-type="bibr">14</xref>]. The H2N3 influenza viruses isolated from pigs show antigenic cross-reactivity with North American and
Eurasian H2 avian influenza viruses [<xref rid="r13" ref-type="bibr">13</xref>]. However, information regarding the H2 influenza viruses recently isolated in Asia, particularly on the antigenicity of such viruses is limited. To
prepare in case of H2 influenza virus transmission to the human population from animals, the characterization of genetic and antigenic properties of recent isolates, including viruses recently isolated from wild bird in Asia is
greatly needed. Since 1996, we have conducted intensive surveillance of avian influenza in wild waterfowl in Hokkaido, Japan and Mongolia to monitor viruses that are maintained in the nesting lakes in Siberia and spread southward
along with their migration in autumn. We reported the isolation of influenza viruses of various subtypes including H2 influenza viruses [<xref rid="r7" ref-type="bibr">7</xref>, <xref rid="r10" ref-type="bibr">10</xref>, <xref rid="r29" ref-type="bibr">29</xref>]. All viruses isolated in the surveillance study are stored in our influenza virus library (<ext-link ext-link-type="uri" xlink:href="http://virusdb.czc.hokudai.ac.jp/">http://virusdb.czc.hokudai.ac.jp/</ext-link>).</p><p>Previous studies demonstrated that cold-adapted live vaccines generated by human and avian H2 influenza viruses induce effective immunity against challenge using parental strains in mouse and ferret models [<xref rid="r2" ref-type="bibr">2</xref>, <xref rid="r3" ref-type="bibr">3</xref>]. However, studies on the preparation of inactivated vaccine against H2 influenza are still limited. The aim of the present study is to evaluate the efficacy of an
inactivated whole virus particle vaccine prepared from viruses recently isolated from wild birds in Asia based on its antigenicity, immunogenicity, and protective effects against challenge with swine H2 influenza virus in mice.</p><sec sec-type="materials|methods" id="s1"><title>MATERIALS AND METHODS</title><sec><title>Viruses and cells</title><p>Influenza viruses, A/swine/Missouri/2124514/2006 (H2N3) and A/mallard/Alberta/884/1984 (H2N5), were kindly provided by Dr. Richard J. Webby and Dr. Robert G. Webster, St. Jude Children’s Research Hospital, U.S.A.
A/Singapore/1/1957 (H2N2) and A/duck/Hong Kong/278/1978 (H2N9) were kindly provided by Dr. Ken F. Shortridge, the University of Hong Kong, Hong Kong SAR. A/pintail/Shimane/1086/1981 (H2N3) was kindly provided by Dr. Koichi Otsuki,
Tottori University, Japan. A/duck/Alaska/5111/1994 (H2N3), A/duck/Hokkaido/162/2013 (H2N1), and other H2 influenza viruses stored in our library (<xref rid="tbl_001" ref-type="table">Table 1</xref><table-wrap id="tbl_001" orientation="portrait" position="float"><label>Table 1.</label><caption><title>Accession numbers of the HA gene sequences submitted to the GenBank/EMBL/DDBJ in this study</title></caption><table frame="hsides" rules="groups"><thead><tr><th align="center" rowspan="1" colspan="1">Viruses</th><th align="center" rowspan="1" colspan="1">Accession No.</th></tr></thead><tbody><tr><td align="left" rowspan="1" colspan="1"><bold>A/pintail/Shimane/1086/1981 (H2N3)</bold></td><td align="center" rowspan="1" colspan="1">LC042004</td></tr><tr><td align="left" rowspan="1" colspan="1"><bold>A/whistling swan/Shimane/1447/1982 (H2N3)</bold></td><td align="center" rowspan="1" colspan="1">LC042007</td></tr><tr><td align="left" rowspan="1" colspan="1"><bold>A/duck/Alaska/5111/1994 (H2N3)</bold></td><td align="center" rowspan="1" colspan="1">LC042003</td></tr><tr><td align="left" rowspan="1" colspan="1"><bold>A/swan/Shimane/221/1999 (H2N3)</bold></td><td align="center" rowspan="1" colspan="1">LC042005</td></tr><tr><td align="left" rowspan="1" colspan="1"><bold>A/duck/Hokkaido/96/2001 (H2N3)</bold></td><td align="center" rowspan="1" colspan="1">LC041992</td></tr><tr><td align="left" rowspan="1" colspan="1"><bold>A/duck/Mongolia/210/2003 (H2N3)</bold></td><td align="center" rowspan="1" colspan="1">LC041993</td></tr><tr><td align="left" rowspan="1" colspan="1"><bold>A/duck/Hokkaido/W163/2010 (H2N3)</bold></td><td align="center" rowspan="1" colspan="1">LC042006</td></tr><tr><td align="left" rowspan="1" colspan="1"><bold>A/duck/Hokkaido/491008/2011 (H2N3)</bold></td><td align="center" rowspan="1" colspan="1">LC041994</td></tr><tr><td align="left" rowspan="1" colspan="1"><bold>A/duck/Hokkaido/162/2013 (H2N1)</bold></td><td align="center" rowspan="1" colspan="1">LC041995</td></tr><tr><td align="left" rowspan="1" colspan="1">A/duck/Hokkaido/178/2013 (H2N1)</td><td align="center" rowspan="1" colspan="1">LC041996</td></tr><tr><td align="left" rowspan="1" colspan="1">A/duck/Hokkaido/179/2013 (H2N1)</td><td align="center" rowspan="1" colspan="1">LC041997</td></tr><tr><td align="left" rowspan="1" colspan="1">A/duck/Hokkaido/181/2013 (H2N1)</td><td align="center" rowspan="1" colspan="1">LC041998</td></tr><tr><td align="left" rowspan="1" colspan="1">A/duck/Hokkaido/183/2013 (H2N1)</td><td align="center" rowspan="1" colspan="1">LC041999</td></tr><tr><td align="left" rowspan="1" colspan="1">A/duck/Hokkaido/189/2013 (H2N1)</td><td align="center" rowspan="1" colspan="1">LC042000</td></tr><tr><td align="left" rowspan="1" colspan="1">A/duck/Hokkaido/203/2013 (H2N1)</td><td align="center" rowspan="1" colspan="1">LC042001</td></tr><tr><td align="left" rowspan="1" colspan="1">A/duck/Hokkaido/211/2013 (H2N1)</td><td align="center" rowspan="1" colspan="1">LC042002</td></tr></tbody></table><table-wrap-foot><p>Bold: Viruses indicated in the phylogenetic tree (<xref ref-type="fig" rid="fig_001">Fig. 1</xref>).</p></table-wrap-foot></table-wrap>) were isolated from fecal samples of migratory ducks in our surveillance study [<xref rid="r7" ref-type="bibr">7</xref>, <xref rid="r10" ref-type="bibr">10</xref>]. All viruses used in the present study were
propagated in 10-day-old embryonated chicken eggs at 35°C for 48 hr, and infectious allantoic fluids were stored at −80°C until use. Madin-Darby canine kidney (MDCK) cells were grown in minimum essential medium (MEM) (Nissui
Pharmaceutical, Tokyo, Japan) supplemented with 10% inactivated calf serum and antibiotics and were used for titration of viral infectivity.</p></sec><sec><title>Sequencing and phylogenetic analysis</title><p>Viral RNA was extracted from the allantoic fluids of embryonated chicken eggs using TRIzol LS Reagent (Life Technologies, Carlsbad, CA, U.S.A.) and reverse-transcribed with the Uni 12 primer (5′-AGCAAAAGCAGG-3′) and M-MLV Reverse
Transcriptase (Life Technologies) [<xref rid="r8" ref-type="bibr">8</xref>]. The full-length HA gene segment was amplified by polymerase chain reaction (PCR) using Ex-Taq (TaKaRa, Shiga, Japan) and gene-specific primer sets [<xref rid="r8" ref-type="bibr">8</xref>]. Direct sequencing of each gene segment was performed using the BigDye Terminator v3.1 Cycle Sequencing Kit (Life Technologies) and an auto-sequencer 3500 Genetic Analyzer (Life Technologies).
Sequencing data were analyzed and aligned using Clustal W using GENETYX<sup>®</sup> Network version 12 (Genetyx Co., Tokyo, Japan). The nucleotide sequences were phylogenetically analyzed by the maximum-likelihood (ML) method
using MEGA 6.0 software (<ext-link ext-link-type="uri" xlink:href="http://www.megasoftware.net/">http://www.megasoftware.net/</ext-link>). Sequence data for H2 HA genes were compared with reference sequences selected and obtained
from GenBank/EMBL/DDBJ.</p></sec><sec><title>Antigenic analysis</title><p>To analyze the antigenic properties of H2 influenza viruses, the hemagglutination inhibition (HI) test was performed using hyper-immunized chicken antisera against 7 representative strains of H2 viruses. Twenty-five microliters
of 8 hemagglutination units of the test virus was added to 25 <italic>µl</italic> of 2-fold dilutions of each antiserum in PBS and incubated at room temperature for 30 min. After the incubation, 50 <italic>µl</italic> of 0.5%
chicken red blood cells in PBS was added and incubated at room temperature for 30 min. HI titers were expressed as the reciprocal of the highest serum dilution showing complete inhibition of hemagglutination.</p></sec><sec><title>Vaccine preparation</title><p>The selected vaccine strain, A/duck/Hokkaido/162/2013 (H2N1), and the challenge strain, A/swine/Missouri/2124514/2006 (H2N3), were inoculated into the allantoic cavities of 10-day-old embryonated chicken eggs and propagated at
35°C for 48 hr. The viruses in the allantoic fluids were purified by differential centrifugation and sedimentation through a sucrose gradient modified from Kida <italic>et al</italic> [<xref rid="r15" ref-type="bibr">15</xref>].
Briefly, allantoic fluids were ultracentrifuged and pellets were layered onto 10 to 50% sucrose density gradient and ultracentrifuged. The fractions containing viruses were collected based on the sucrose concentration,
hemagglutination titer, and protein concentration. Whole virus particles were pelleted from the sucrose fractions by ultracentrifugation and suspended in a small volume of PBS. The purified viruses were inactivated by incubation
in 0.1% formalin at 4°C for 7 days. Virus inactivation was confirmed by inoculation of the formalin-treated samples into embryonated chicken eggs. The total protein concentration was measured using the BCA Protein Assay Reagent
(Thermo Fisher Scientific, Waltham, MA, U.S.A.). Each viral protein in the vaccine was separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and the relative amounts of the hemagglutinin (HA) protein
were assumed as a ratio of the HA protein in the total protein using ImageJ (<ext-link ext-link-type="uri" xlink:href="http://rsb.info.nih.gov/ij/index.html">http://rsb.info.nih.gov/ij/index.html</ext-link>).</p></sec><sec><title>Potency test of vaccines in mice</title><p>Each whole inactivated vaccine of A/duck/Hokkaido/162/2013 (H2N1) or A/swine/Missouri/2124514/2006 (H2N3) (100 <italic>µ</italic>g total protein/vaccine, containing 26.4 and 21.5 <italic>µ</italic>g HA protein respectively) was
injected subcutaneously into 10 4-week-old female BALB/c mice (Japan SLC, Shizuoka, Japan). PBS was injected into control mice. Serum samples were collected from each mouse 21 days after the vaccination, and all mice were
challenged with 10<sup>5.0</sup> times the 50% tissue culture infectious dose (TCID<sub>50</sub>) /30 <italic>µl</italic> of A/swine/Missouri/2124514/2006 (H2N3) intranasally under anesthesia. Each vaccine (100 <italic>µ</italic>g
total protein/vaccine, containing 26.4 and 21.5 <italic>µ</italic>g HA protein respectively) was also subcutaneously injected twice into 10 mice with a 2-week interval. Fourteen days after the vaccination, serum samples were
collected from each mouse and each vaccine was injected into the mice again at the same dose as first injection. After another 2-week interval, serum samples were collected from each mouse, and all of the mice were challenged with
10<sup>5.0</sup> TCID<sub>50</sub>/30 <italic>µl</italic> of A/swine/Missouri/2124514/2006 (H2N3) intranasally under anesthesia. Three days after the challenge, 5 mice from each group were sacrificed, and their lungs were
collected. Titers of recovered viruses from the lung homogenates were measured using MDCK cells. The other 5 mice from each group were observed clinical signs for 14 days. The neutralizing antibody titers of mice sera against
homologous viruses and A/swine/Missouri/2124514/2006 (H2N3) were determined by serum neutralization test using MDCK cells.</p></sec><sec><title>Virus titration</title><p>Ten-fold dilutions of virus samples or mice lung homogenates were inoculated onto confluent monolayers of MDCK cells and incubated at 35°C for 1 hr. Unbound viruses were removed and the cells were washed with PBS. The cells were
subsequently overlaid with MEM containing 5 <italic>µ</italic>g/m<italic>l</italic> acetylated trypsin (Sigma-Aldrich, St. Louis, MO, U.S.A.). Titers were determined as the product of the reciprocal value of the highest virus
dilution showing 50% of the cytopathic effects after 72 hr incubation and expressed as TCID<sub>50</sub>.</p></sec><sec><title>Serum neutralization test</title><p>Serum neutralizing antibody titers were measured according to the method of Sakabe <italic>et al</italic> [<xref rid="r25" ref-type="bibr">25</xref>]. Briefly, test sera and 100 TCID<sub>50</sub> of A/swine/Missouri/2124514/2006
(H2N3) or vaccine strain virus were mixed and incubated for 1 hr at room temperature. The mixture was inoculated onto MDCK cells and incubated at 35°C for 1 hr. Unbound viruses were removed and the cells were washed with PBS. The
cells were subsequently incubated in MEM containing 5 <italic>µ</italic>g/m<italic>l</italic> acetylated trypsin (Sigma-Aldrich). Cytopathic effects were observed after 72 hr incubation and neutralizing antibody titers were
determined as the reciprocal of the serum dilution yielding 50% inhibition of the cytopathic effects.</p></sec><sec><title>Ethics statement</title><p>Animal experiments were authorized by the Institutional Animal Care and Use Committee of the Graduate School of Veterinary Medicine, Hokkaido University (approved numbers: 13-0104, 15-0063), and all experiments were performed
according to the guidelines of this committee.</p></sec></sec><sec sec-type="results" id="s2"><title>RESULTS</title><sec><title>Genetic analysis of H2 influenza viruses</title><p>Nucleotide sequences of HA genes of the H2 viruses in the influenza virus library were determined and phylogenetically analyzed along with reference sequences available in the public database (<xref rid="tbl_001" ref-type="table">Table 1</xref> and <xref ref-type="fig" rid="fig_001">Fig. 1</xref><fig orientation="portrait" fig-type="figure" id="fig_001" position="float"><label>Fig. 1.</label><caption><p>Phylogenetic tree of H2 HA genes of influenza viruses. Full-length nucleotide sequences of the HA gene were used for phylogenetic analysis using the ML method. Horizontal distances are proportional to the minimum number of
nucleotide differences required to join nodes and sequences. Numbers at each node indicate the confidence level in bootstrap analysis with 1,000 replications. The representative viruses of each cluster are shown in bold. The
vaccine strain is highlighted and the challenge strain is underlined.</p></caption><graphic xlink:href="jvms-79-1815-g001"></graphic></fig>). Nucleotide sequences of viruses isolated in Hokkaido in 2013 showed high similarity (99.7–100%) and A/duck/Hokkaido/162/2013 (H2N1) was selected as a representative strain. Based on the results of phylogenetic analysis,
the H2 HA genes were classified into Eurasian and North American lineages as the previous study described [<xref rid="r26" ref-type="bibr">26</xref>]. The Eurasian linage included viruses isolated in Asia, Europe, and Alaska,
while the North American linage included viruses mainly isolated in North America. Viruses belonging to the Eurasian linage were further divided into 4 clusters. Viruses in cluster 1 were avian influenza viruses isolated before
the 1980’s. Human H2N2 influenza viruses formed a single cluster, cluster 2. This study revealed that avian H2 influenza viruses isolated in Japan in the 1980’s (represented by A/pintail/Shimane/1086/1981 (H2N3) in the
phylogenetic tree) belonged to cluster 3, along with European isolates around the same period. Recent isolates from avian species in European and Asian countries formed cluster 4. These results clearly demonstrate that H2
influenza viruses recently circulating among birds are genetically distant from human H2N2 viruses. Swine H2N3 viruses belong to the North American lineage and no avian viruses recently isolated in the East Asia region are
genetically close to the swine H2N3 viruses.</p></sec><sec><title>Antigenic analysis of H2 influenza viruses</title><p>Seven H2 influenza virus strains representatives of each genetic cluster were selected and antigenically analyzed by HI test (<xref rid="tbl_002" ref-type="table">Table 2</xref><table-wrap id="tbl_002" orientation="portrait" position="float"><label>Table 2.</label><caption><title>The cross-reactivity of H2 influenza viruses with chicken antisera to representative strains of each lineage in HI test</title></caption><table frame="hsides" rules="groups"><thead><tr><th rowspan="2" align="center" colspan="1">Lineages</th><th rowspan="2" align="center" colspan="1">Clusters</th><th rowspan="2" align="center" colspan="1">Viruses</th><th colspan="7" align="center" rowspan="1">HI titers of the antisera<hr></hr></th></tr><tr><th align="center" rowspan="1" colspan="1">Dk/HK/78</th><th align="center" rowspan="1" colspan="1">Sing/57</th><th align="center" rowspan="1" colspan="1">Pin/SMN/81</th><th align="center" rowspan="1" colspan="1">Dk/Hok/13</th><th align="center" rowspan="1" colspan="1">Mal/ALB/84</th><th align="center" rowspan="1" colspan="1">Dk/AK/94</th><th align="center" rowspan="1" colspan="1">Swine/MO/06</th></tr></thead><tbody><tr><td align="left" valign="top" rowspan="1" colspan="1">Eurasian</td><td align="left" valign="top" rowspan="1" colspan="1">1</td><td align="left" valign="top" rowspan="1" colspan="1">Dk/HK/78 (H2N9)</td><td align="center" valign="top" rowspan="1" colspan="1"><underline>320</underline></td><td align="center" valign="top" rowspan="1" colspan="1">2,560</td><td align="center" valign="top" rowspan="1" colspan="1">640</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1">640</td><td align="center" valign="top" rowspan="1" colspan="1">2,560</td><td align="center" valign="top" rowspan="1" colspan="1">640</td></tr><tr><td align="left" valign="top" rowspan="1" colspan="1"></td><td align="left" valign="top" rowspan="1" colspan="1">2 (Human)</td><td align="left" valign="top" rowspan="1" colspan="1">Sing/57 (H2N2)</td><td align="center" valign="top" rowspan="1" colspan="1">640</td><td align="center" valign="top" rowspan="1" colspan="1"><underline>5,120</underline></td><td align="center" valign="top" rowspan="1" colspan="1">1,280</td><td align="center" valign="top" rowspan="1" colspan="1">640</td><td align="center" valign="top" rowspan="1" colspan="1">2,560</td><td align="center" valign="top" rowspan="1" colspan="1">2,560</td><td align="center" valign="top" rowspan="1" colspan="1">640</td></tr><tr><td align="left" valign="top" rowspan="1" colspan="1"></td><td align="left" valign="top" rowspan="1" colspan="1">3</td><td align="left" valign="top" rowspan="1" colspan="1">Pin/SMN/81 (H2N3)</td><td align="center" valign="top" rowspan="1" colspan="1">40</td><td align="center" valign="top" rowspan="1" colspan="1">2,560</td><td align="center" valign="top" rowspan="1" colspan="1"><underline>320</underline></td><td align="center" valign="top" rowspan="1" colspan="1">160</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1">1,280</td><td align="center" valign="top" rowspan="1" colspan="1">320</td></tr><tr><td align="left" valign="top" rowspan="1" colspan="1"></td><td align="left" valign="top" rowspan="1" colspan="1">4</td><td align="left" valign="top" rowspan="1" colspan="1">Dk/Hok/13 (H2N1)</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1">2,560</td><td align="center" valign="top" rowspan="1" colspan="1">640</td><td align="center" valign="top" rowspan="1" colspan="1"><underline>640</underline></td><td align="center" valign="top" rowspan="1" colspan="1">1,280</td><td align="center" valign="top" rowspan="1" colspan="1">1,280</td><td align="center" valign="top" rowspan="1" colspan="1">640</td></tr><tr><td align="left" valign="top" colspan="2" rowspan="1">North American</td><td align="left" valign="top" rowspan="1" colspan="1">Mal/ALB/84 (H2N5)</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1">1,280</td><td align="center" valign="top" rowspan="1" colspan="1">640</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1"><underline>1,280</underline></td><td align="center" valign="top" rowspan="1" colspan="1">2,560</td><td align="center" valign="top" rowspan="1" colspan="1">1,280</td></tr><tr><td align="left" valign="top" rowspan="1" colspan="1"></td><td align="left" valign="top" rowspan="1" colspan="1"></td><td align="left" valign="top" rowspan="1" colspan="1">Dk/AK/94 (H2N3)</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1">2,560</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1">640</td><td align="center" valign="top" rowspan="1" colspan="1"><underline>2,560</underline></td><td align="center" valign="top" rowspan="1" colspan="1">1,280</td></tr><tr><td align="left" valign="top" rowspan="1" colspan="1"></td><td align="left" valign="top" rowspan="1" colspan="1">(Swine)</td><td align="left" valign="top" rowspan="1" colspan="1">Swine/MO/06 (H2N3)</td><td align="center" valign="top" rowspan="1" colspan="1">640</td><td align="center" valign="top" rowspan="1" colspan="1">2,560</td><td align="center" valign="top" rowspan="1" colspan="1">1,280</td><td align="center" valign="top" rowspan="1" colspan="1">640</td><td align="center" valign="top" rowspan="1" colspan="1">5,120</td><td align="center" valign="top" rowspan="1" colspan="1">2,560</td><td align="center" valign="top" rowspan="1" colspan="1"><underline>2,560</underline></td></tr></tbody></table><table-wrap-foot><p>Homologous titers are underlined. Abbreviations: Dk/HK/78, A/duck/Hong Kong/278/1978 (H2N9); Sing/57, A/Singapore/1/1957 (H2N2); Pin/SMN/81, A/pintail/Shimane/1086/1981 (H2N3); Dk/Hok/13, A/duck/Hokkaido/162/2013 (H2N1);
Mal/ALB/84, A/mallard/Alberta/884/1984 (H2N5); Dk/AK/94, A/duck/Alaska/5111/1994 (H2N3); Swine/MO/06, A/swine/Missouri/2124514/2006 (H2N3).</p></table-wrap-foot></table-wrap>). Antisera against the avian H2 influenza viruses, A/duck/Hong Kong/278/1978 (H2N9), A/pintail/Shimane/1086/1981 (H2N3), A/duck/Hokkaido/162/2013 (H2N1), A/mallard/Alberta/884/1984 (H2N5), and A/duck/Alaska/5111/1994
(H2N3), reacted with the human H2N2 influenza virus, A/Singapore/1/1957 (H2N2). Antisera against viruses belonging to the Eurasian lineage showed cross-reactivity with the North American linage, and <italic>vice versa</italic>.
All antisera reacted with the swine H2N3 virus at HI titers similar to those of the homologous viruses.</p></sec><sec><title>Potency test of the vaccine against H2 influenza virus in mice</title><p>Based on the results of antigenic analysis, all viruses tested in the present study showed cross-reactivity with viruses belonging to the other genetic groups. Thus, the most recent isolate at the beginning of this study,
A/duck/Hokkaido/162/2013 (H2N1), was assumed to be vaccine candidates and used in following examinations. Neutralizing antibody titers of sera collected from mice immunized once with either A/duck/Hokkaido/162/2013 (H2N1) or
A/swine/Missouri/2124514/2006 (H2N3) were low (<xref rid="tbl_003" ref-type="table">Table 3</xref><table-wrap id="tbl_003" orientation="portrait" position="float"><label>Table 3.</label><caption><title>Neutralizing antibody titers of mice sera injected once with vaccines and virus recovery from mice lungs after challenge with A/swine/Missouri/2124514/2006 (H2N3)</title></caption><table frame="hsides" rules="groups"><thead><tr><th rowspan="2" align="center" colspan="1">Vaccine strain</th><th colspan="10" align="center" rowspan="1">Neutralizing titer of sera at 21 days post immunization against<hr></hr></th><th colspan="5" rowspan="2" align="center">Virus titer in lungs at 3 days post challenge (log<sub>10</sub> TCID<sub>50</sub>/g)</th></tr><tr><th colspan="5" align="center" rowspan="1">Dk/Hok/13 (H2N1)</th><th colspan="5" align="center" rowspan="1">Swine/MO/06 (H2N3)</th></tr></thead><tbody><tr><td align="left" valign="top" rowspan="1" colspan="1">Dk/Hok/13 (H2N1)<sup>a)</sup></td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1">40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1">80</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"> 80</td><td align="center" valign="top" rowspan="1" colspan="1">≤3.0</td><td align="center" valign="top" rowspan="1" colspan="1">4.3</td><td align="center" valign="top" rowspan="1" colspan="1">≤2.8</td><td align="center" valign="top" rowspan="1" colspan="1">≤3.3</td><td align="center" valign="top" rowspan="1" colspan="1">≤3.0</td></tr><tr><td align="left" valign="top" rowspan="1" colspan="1">Swine/MO/06 (H2N3)<sup>b)</sup></td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">80</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1">40</td><td align="center" valign="top" rowspan="1" colspan="1">40</td><td align="center" valign="top" rowspan="1" colspan="1">160</td><td align="center" valign="top" rowspan="1" colspan="1">≤2.8</td><td align="center" valign="top" rowspan="1" colspan="1">≤2.8</td><td align="center" valign="top" rowspan="1" colspan="1">≤3.0</td><td align="center" valign="top" rowspan="1" colspan="1">≤2.8</td><td align="center" valign="top" rowspan="1" colspan="1">≤2.8</td></tr><tr><td align="left" valign="top" rowspan="1" colspan="1">PBS</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1">6.6</td><td align="center" valign="top" rowspan="1" colspan="1">7.0</td><td align="center" valign="top" rowspan="1" colspan="1">5.8</td><td align="center" valign="top" rowspan="1" colspan="1">6.3</td><td align="center" valign="top" rowspan="1" colspan="1">6.0</td></tr></tbody></table><table-wrap-foot><p>-: Not tested, a) A/duck/Hokkaido/162/2013 (H2N1), b) A/swine/Missouri/2124514/2006 (H2N3).</p></table-wrap-foot></table-wrap>). In contrast, the neutralizing antibody titers of mice sera injected twice with either vaccines were reached up to 1:320 against the homologous virus (<xref rid="tbl_004" ref-type="table">Table 4</xref><table-wrap id="tbl_004" orientation="portrait" position="float"><label>Table 4.</label><caption><title>Neutralizing antibody titers of mice sera injected twice with vaccines and virus recovery from mice lungs after challenge with A/swine/Missouri/2124514/2006 (H2N3)</title></caption><table frame="hsides" rules="groups"><thead><tr><th rowspan="2" align="center" colspan="1">Vaccine strain</th><th colspan="10" align="center" rowspan="1">Neutralizing titer of sera at 28 days post immunization against<hr></hr></th><th colspan="5" rowspan="2" align="center">Virus titer in lungs at 3 days post challenge (log<sub>10</sub> TCID<sub>50</sub>/g)</th></tr><tr><th colspan="5" align="center" rowspan="1">Dk/Hok/13 (H2N1)</th><th colspan="5" align="center" rowspan="1">Swine/MO/06 (H2N3)</th></tr></thead><tbody><tr><td align="left" valign="top" rowspan="1" colspan="1">Dk/Hok/13 (H2N1)<sup>a)</sup></td><td align="center" valign="top" rowspan="1" colspan="1">160</td><td align="center" valign="top" rowspan="1" colspan="1">80</td><td align="center" valign="top" rowspan="1" colspan="1">80</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1">40</td><td align="center" valign="top" rowspan="1" colspan="1">80</td><td align="center" valign="top" rowspan="1" colspan="1">160</td><td align="center" valign="top" rowspan="1" colspan="1">40</td><td align="center" valign="top" rowspan="1" colspan="1">80</td><td align="center" valign="top" rowspan="1" colspan="1"><</td><td align="center" valign="top" rowspan="1" colspan="1"><</td><td align="center" valign="top" rowspan="1" colspan="1"><</td><td align="center" valign="top" rowspan="1" colspan="1"><</td><td align="center" valign="top" rowspan="1" colspan="1">< </td></tr><tr><td align="left" valign="top" rowspan="1" colspan="1">Swine/MO/06 (H2N3)<sup>b)</sup></td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">160</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1">160</td><td align="center" valign="top" rowspan="1" colspan="1">320</td><td align="center" valign="top" rowspan="1" colspan="1"><</td><td align="center" valign="top" rowspan="1" colspan="1"><</td><td align="center" valign="top" rowspan="1" colspan="1"><</td><td align="center" valign="top" rowspan="1" colspan="1"><</td><td align="center" valign="top" rowspan="1" colspan="1">< </td></tr><tr><td align="left" valign="top" rowspan="1" colspan="1">PBS</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1">-</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1"><40</td><td align="center" valign="top" rowspan="1" colspan="1">6.5</td><td align="center" valign="top" rowspan="1" colspan="1">6.3</td><td align="center" valign="top" rowspan="1" colspan="1">6.5</td><td align="center" valign="top" rowspan="1" colspan="1">6.0</td><td align="center" valign="top" rowspan="1" colspan="1">5.7</td></tr></tbody></table><table-wrap-foot><p>-: Not tested, <: Not detected, a) A/duck/Hokkaido/162/2013 (H2N1), b) A/swine/Missouri/2124514/2006 (H2N3).</p></table-wrap-foot></table-wrap>). The neutralizing antibody titers of sera from mice vaccinated twice with A/duck/Hokkaido/162/2013 (H2N1) against A/swine/Missouri/2124514/2006 (H2N3) were 1:40–1:160. The virus titers in the lungs of the mice
immunized once with either A/duck/Hokkaido/162/2013 (H2N1) or A/swine/Missouri/2124514/2006 (H2N3) were restrained at a low level compared with the lungs of mice in non-vaccinated group (<xref rid="tbl_003" ref-type="table">Table
3</xref>). The virus titers in the lungs of the mice injected twice with either A/duck/Hokkaido/162/2013 (H2N1) or A/swine/Missouri/2124514/2006 (H2N3) were below the detection limit despite individual differences in
neutralizing antibody titers (<xref rid="tbl_004" ref-type="table">Table 4</xref>). These results indicated the A/duck/Hokkaido/162/2013 (H2N1) vaccine induced immunity in mice sufficient to reduce the impacts of the challenge
strain, A/swine/Missouri/2124514/2006 (H2N3), in the lungs comparable to that of the homologous vaccine strain, A/swine/Missouri/2124514/2006 (H2N3). All of the mice in this study inoculated with 10<sup>5.0</sup> TCID<sub>50</sub>of the swine H2N3 virus survived during observation period and showed no overt clinical signs including body weight loss.</p></sec></sec><sec sec-type="discussion" id="s3"><title>DISCUSSION</title><p>Vaccination is the most effective control measure for human pandemic influenza and the preparation of vaccines for future H2 influenza pandemics is necessary [<xref rid="r20" ref-type="bibr">20</xref>]. Our results demonstrated
that an inactivated whole virus particle vaccine prepared from recent avian H2 influenza virus, A/duck/Hokkaido/162/2013 (H2N1), is effective for use in future human pandemics. A/duck/Hokkaido/162/2013 (H2N1) showed broad antigenic
cross-reactivity and thus was selected as the vaccine candidate strain in this study. The inactivated vaccine prepared from A/duck/Hokkaido/162/2013 (H2N1) induced neutralizing antibodies against the homologous virus and
A/swine/Missouri/2124514/2006 (H2N3) in mice after 2 subcutaneous injections. The inactivated vaccine was also sufficiently protective to reduce the impact of the challenge with A/swine/Missouri/2124514/2006 (H2N3) at a level
comparable to that of the vaccine prepared from the homologous strain of the challenge virus.</p><p>Inactivated whole virus particle influenza vaccines are more effective than split influenza vaccines [<xref rid="r1" ref-type="bibr">1</xref>, <xref rid="r9" ref-type="bibr">9</xref>, <xref rid="r20" ref-type="bibr">20</xref>,
<xref rid="r23" ref-type="bibr">23</xref>]. Lenny <italic>et al.</italic> reported that monovalent or multivalent inactivated whole virus particle vaccines generated from A/Singapore/1/1957 (H2N2), A/duck/Hong Kong/319/1978
(H2N2), or A/swine/Missouri/2124514/2006 (H2N3) are effective against a challenge with one of the three viruses in mouse model [<xref rid="r18" ref-type="bibr">18</xref>].</p><p>Our findings supported the effectiveness of inactivated whole virus particle vaccine against H2 influenza because avian H2 influenza viruses currently circulating among birds are also effective. Our inactivated vaccine prepared
from A/duck/Hokkaido/162/2013 (H2N1) required 2 rounds of vaccination to induce neutralizing antibodies in mice to A/swine/Missouri/2124514/2006 (H2N3); thus, the dosage of vaccine and the most effective administration strategy
should be considered to improve the efficacy of this vaccine.</p><p>We have established an influenza virus library for storing various influenza viruses for use as seed for vaccines. Influenza viruses of 144 combinations including 16 HA and 9 neuraminidase subtypes isolated from animals or
generated in our laboratory have been stored in the library. Our previous studies revealed that whole virus particle vaccines prepared from this library induce effective immunity against infections with H1, H5, H6, H7 and H9
influenza viruses in mice and macaque models [<xref rid="r4" ref-type="bibr">4</xref>, <xref rid="r11" ref-type="bibr">11</xref>, <xref rid="r12" ref-type="bibr">12</xref>, <xref rid="r21" ref-type="bibr">21</xref>,<xref rid="r22" ref-type="bibr">22</xref>,<xref rid="r23" ref-type="bibr">23</xref>]. In the present study, the vaccine candidate strain against H2 influenza selected from the influenza library is shown to be potentially useful for a
future H2 influenza pandemic. Our annual influenza surveillance in wild birds in Japan and Mongolia effectively monitors virus circulation in wild birds in East Asian countries and also provides a variety of influenza viruses [<xref rid="r7" ref-type="bibr">7</xref>, <xref rid="r29" ref-type="bibr">29</xref>]. Thus, our library is updated each season, providing specimens from which we might gain novel information about the antigenicity of H2 influenza viruses
circulating in wild birds in East Asian countries.</p><p>In further studies, monitoring of introduction of H2 influenza virus into pig population and emergence of mammalian adapted H2 influenza viruses is important for early response to a human pandemic. In addition, the continuous
surveillance and antigenic analysis of H2 influenza viruses in both wild birds and poultry are necessary to prepare for a future pandemic and allow for rapid vaccine preparation.</p></sec></body><back><ack><p>We wish to acknowledge Dr. R. J. Webby and Dr. R. G. Webster, St. Jude Children’s Research Hospital, Dr. K. F. Shortridge, the University of Hong Kong, and Dr. K. Otsuki, Tottori University for kindly providing the viruses used in
this study. The present work was supported in part by the Program for Leading Graduate Schools (F01) from the Japan Society for the Promotion of Science (JSPS). This research is partially supported by the Japan Initiative for Global
Research Network on Infectious Diseases (J-GRID) from Ministry of Education, Culture, Sport, Science & Technology in Japan, and Japan Agency for Medical Research and Development (AMED). M. S. is supported by JSPS Research
Fellowships for young scientists.</p></ack><ref-list><title>REFERENCES</title><ref id="r1"><label>1</label><mixed-citation publication-type="journal"><person-group><name><surname>Arikata</surname><given-names>M.</given-names></name><name><surname>Itoh</surname><given-names>Y.</given-names></name><name><surname>Okamatsu</surname><given-names>M.</given-names></name><name><surname>Maeda</surname><given-names>T.</given-names></name><name><surname>Shiina</surname><given-names>T.</given-names></name><name><surname>Tanaka</surname><given-names>K.</given-names></name><name><surname>Suzuki</surname><given-names>S.</given-names></name><name><surname>Nakayama</surname><given-names>M.</given-names></name><name><surname>Sakoda</surname><given-names>Y.</given-names></name><name><surname>Ishigaki</surname><given-names>H.</given-names></name><name><surname>Takada</surname><given-names>A.</given-names></name><name><surname>Ishida</surname><given-names>H.</given-names></name><name><surname>Soda</surname><given-names>K.</given-names></name><name><surname>Pham</surname><given-names>V. L.</given-names></name><name><surname>Tsuchiya</surname><given-names>H.</given-names></name><name><surname>Nakamura</surname><given-names>S.</given-names></name><name><surname>Torii</surname><given-names>R.</given-names></name><name><surname>Shimizu</surname><given-names>T.</given-names></name><name><surname>Inoko</surname><given-names>H.</given-names></name><name><surname>Ohkubo</surname><given-names>I.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name><name><surname>Ogasawara</surname><given-names>K.</given-names></name></person-group><year>2012</year>. <article-title>Memory immune responses against pandemic (H1N1) 2009 influenza virus induced by a whole particle vaccine in cynomolgus monkeys carrying Mafa-A1*052:02</article-title>.
<source><italic>PLoS ONE</italic></source><volume>7</volume>: <fpage>e37220</fpage>. doi: <pub-id pub-id-type="doi">10.1371/journal.pone.0037220</pub-id><pub-id pub-id-type="pmid">22623997</pub-id></mixed-citation></ref><ref id="r2"><label>2</label><mixed-citation publication-type="journal"><person-group><name><surname>Chen</surname><given-names>G. L.</given-names></name><name><surname>Lamirande</surname><given-names>E. W.</given-names></name><name><surname>Jin</surname><given-names>H.</given-names></name><name><surname>Kemble</surname><given-names>G.</given-names></name><name><surname>Subbarao</surname><given-names>K.</given-names></name></person-group><year>2010</year>. <article-title>Safety, immunogencity, and efficacy of a cold-adapted A/Ann Arbor/6/60 (H2N2) vaccine in mice and ferrets</article-title>.
<source><italic>Virology</italic></source><volume>398</volume>: <fpage>109</fpage>–<lpage>114</lpage>. doi: <pub-id pub-id-type="doi">10.1016/j.virol.2009.12.003</pub-id><pub-id pub-id-type="pmid">20034647</pub-id></mixed-citation></ref><ref id="r3"><label>3</label><mixed-citation publication-type="journal"><person-group><name><surname>Chen</surname><given-names>G. L.</given-names></name><name><surname>Lamirande</surname><given-names>E. W.</given-names></name><name><surname>Cheng</surname><given-names>X.</given-names></name><name><surname>Torres-Velez</surname><given-names>F.</given-names></name><name><surname>Orandle</surname><given-names>M.</given-names></name><name><surname>Jin</surname><given-names>H.</given-names></name><name><surname>Kemble</surname><given-names>G.</given-names></name><name><surname>Subbarao</surname><given-names>K.</given-names></name></person-group><year>2014</year>. <article-title>Evaluation of three live attenuated H2 pandemic influenza vaccine candidates in mice and ferrets</article-title>. <source><italic>J. Virol.</italic></source><volume>88</volume>:
<fpage>2867</fpage>–<lpage>2876</lpage>. doi: <pub-id pub-id-type="doi">10.1128/JVI.01829-13</pub-id><pub-id pub-id-type="pmid">24371061</pub-id></mixed-citation></ref><ref id="r4"><label>4</label><mixed-citation publication-type="journal"><person-group><name><surname>Chu</surname><given-names>D. H.</given-names></name><name><surname>Sakoda</surname><given-names>Y.</given-names></name><name><surname>Nishi</surname><given-names>T.</given-names></name><name><surname>Hiono</surname><given-names>T.</given-names></name><name><surname>Shichinohe</surname><given-names>S.</given-names></name><name><surname>Okamatsu</surname><given-names>M.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name></person-group><year>2014</year>. <article-title>Potency of an inactivated influenza vaccine prepared from A/duck/Mongolia/119/2008 (H7N9) against the challenge with A/Anhui/1/2013 (H7N9)</article-title>.
<source><italic>Vaccine</italic></source><volume>32</volume>: <fpage>3473</fpage>–<lpage>3479</lpage>. doi: <pub-id pub-id-type="doi">10.1016/j.vaccine.2014.04.060</pub-id><pub-id pub-id-type="pmid">24793949</pub-id></mixed-citation></ref><ref id="r5"><label>5</label><mixed-citation publication-type="journal"><person-group><name><surname>Govorkova</surname><given-names>E. A.</given-names></name><name><surname>Smirnov YuA</surname></name></person-group><article-title>Cross-protection of mice immunized with different influenza A (H2) strains and challenged with viruses of the same HA subtype</article-title>. <source><italic>Acta
Virol.</italic></source><volume>41</volume>: <fpage>251</fpage>–<lpage>257</lpage>. <pub-id pub-id-type="pmid">9607078</pub-id></mixed-citation></ref><ref id="r6"><label>6</label><mixed-citation publication-type="journal"><person-group><name><surname>Hall</surname><given-names>J. S.</given-names></name><name><surname>Hallgrimsson</surname><given-names>G. T.</given-names></name><name><surname>Suwannanarn</surname><given-names>K.</given-names></name><name><surname>Sreevatsen</surname><given-names>S.</given-names></name><name><surname>Ip</surname><given-names>H. S.</given-names></name><name><surname>Magnusdottir</surname><given-names>E.</given-names></name><name><surname>TeSlaa</surname><given-names>J. L.</given-names></name><name><surname>Nashold</surname><given-names>S. W.</given-names></name><name><surname>Dusek</surname><given-names>R. J.</given-names></name></person-group><year>2014</year>. <article-title>Avian influenza virus ecology in Iceland shorebirds: intercontinental reassortment and movement</article-title>. <source><italic>Infect. Genet.
Evol.</italic></source><volume>28</volume>: <fpage>130</fpage>–<lpage>136</lpage>. doi: <pub-id pub-id-type="doi">10.1016/j.meegid.2014.09.013</pub-id><pub-id pub-id-type="pmid">25239729</pub-id></mixed-citation></ref><ref id="r7"><label>7</label><mixed-citation publication-type="journal"><person-group><name><surname>Hiono</surname><given-names>T.</given-names></name><name><surname>Ohkawara</surname><given-names>A.</given-names></name><name><surname>Ogasawara</surname><given-names>K.</given-names></name><name><surname>Okamatsu</surname><given-names>M.</given-names></name><name><surname>Tamura</surname><given-names>T.</given-names></name><name><surname>Chu</surname><given-names>D. H.</given-names></name><name><surname>Suzuki</surname><given-names>M.</given-names></name><name><surname>Kuribayashi</surname><given-names>S.</given-names></name><name><surname>Shichinohe</surname><given-names>S.</given-names></name><name><surname>Takada</surname><given-names>A.</given-names></name><name><surname>Ogawa</surname><given-names>H.</given-names></name><name><surname>Yoshida</surname><given-names>R.</given-names></name><name><surname>Miyamoto</surname><given-names>H.</given-names></name><name><surname>Nao</surname><given-names>N.</given-names></name><name><surname>Furuyama</surname><given-names>W.</given-names></name><name><surname>Maruyama</surname><given-names>J.</given-names></name><name><surname>Eguchi</surname><given-names>N.</given-names></name><name><surname>Ulziibat</surname><given-names>G.</given-names></name><name><surname>Enkhbold</surname><given-names>B.</given-names></name><name><surname>Shatar</surname><given-names>M.</given-names></name><name><surname>Jargalsaikhan</surname><given-names>T.</given-names></name><name><surname>Byambadorj</surname><given-names>S.</given-names></name><name><surname>Damdinjav</surname><given-names>B.</given-names></name><name><surname>Sakoda</surname><given-names>Y.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name></person-group><year>2015</year>. <article-title>Genetic and antigenic characterization of H5 and H7 influenza viruses isolated from migratory water birds in Hokkaido, Japan and Mongolia from 2010 to 2014</article-title>.
<source><italic>Virus Genes</italic></source><volume>51</volume>: <fpage>57</fpage>–<lpage>68</lpage>. doi: <pub-id pub-id-type="doi">10.1007/s11262-015-1214-9</pub-id><pub-id pub-id-type="pmid">26036326</pub-id></mixed-citation></ref><ref id="r8"><label>8</label><mixed-citation publication-type="journal"><person-group><name><surname>Hoffmann</surname><given-names>E.</given-names></name><name><surname>Stech</surname><given-names>J.</given-names></name><name><surname>Guan</surname><given-names>Y.</given-names></name><name><surname>Webster</surname><given-names>R. G.</given-names></name><name><surname>Perez</surname><given-names>D. R.</given-names></name></person-group><year>2001</year>. <article-title>Universal primer set for the full-length amplification of all influenza A viruses</article-title>. <source><italic>Arch. Virol.</italic></source><volume>146</volume>:
<fpage>2275</fpage>–<lpage>2289</lpage>. doi: <pub-id pub-id-type="doi">10.1007/s007050170002</pub-id><pub-id pub-id-type="pmid">11811679</pub-id></mixed-citation></ref><ref id="r9"><label>9</label><mixed-citation publication-type="journal"><person-group><name><surname>Hovden</surname><given-names>A. O.</given-names></name><name><surname>Brokstad</surname><given-names>K. A.</given-names></name><name><surname>Major</surname><given-names>D.</given-names></name><name><surname>Wood</surname><given-names>J.</given-names></name><name><surname>Haaheim</surname><given-names>L. R.</given-names></name><name><surname>Cox</surname><given-names>R. J.</given-names></name></person-group><year>2009</year>. <article-title>A pilot study of the immune response to whole inactivated avian influenza H7N1 virus vaccine in mice</article-title>. <source><italic>Influenza Other Respi.
Viruses</italic></source><volume>3</volume>: <fpage>21</fpage>–<lpage>28</lpage>. doi: <pub-id pub-id-type="doi">10.1111/j.1750-2659.2009.00075.x</pub-id><pub-id pub-id-type="pmid">19453438</pub-id></mixed-citation></ref><ref id="r10"><label>10</label><mixed-citation publication-type="journal"><person-group><name><surname>Ito</surname><given-names>T.</given-names></name><name><surname>Okazaki</surname><given-names>K.</given-names></name><name><surname>Kawaoka</surname><given-names>Y.</given-names></name><name><surname>Takada</surname><given-names>A.</given-names></name><name><surname>Webster</surname><given-names>R. G.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name></person-group><year>1995</year>. <article-title>Perpetuation of influenza A viruses in Alaskan waterfowl reservoirs</article-title>. <source><italic>Arch. Virol.</italic></source><volume>140</volume>:
<fpage>1163</fpage>–<lpage>1172</lpage>. doi: <pub-id pub-id-type="doi">10.1007/BF01322743</pub-id><pub-id pub-id-type="pmid">7646350</pub-id></mixed-citation></ref><ref id="r11"><label>11</label><mixed-citation publication-type="journal"><person-group><name><surname>Itoh</surname><given-names>Y.</given-names></name><name><surname>Ozaki</surname><given-names>H.</given-names></name><name><surname>Ishigaki</surname><given-names>H.</given-names></name><name><surname>Sakoda</surname><given-names>Y.</given-names></name><name><surname>Nagata</surname><given-names>T.</given-names></name><name><surname>Soda</surname><given-names>K.</given-names></name><name><surname>Isoda</surname><given-names>N.</given-names></name><name><surname>Miyake</surname><given-names>T.</given-names></name><name><surname>Ishida</surname><given-names>H.</given-names></name><name><surname>Okamoto</surname><given-names>K.</given-names></name><name><surname>Nakayama</surname><given-names>M.</given-names></name><name><surname>Tsuchiya</surname><given-names>H.</given-names></name><name><surname>Torii</surname><given-names>R.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name><name><surname>Ogasawara</surname><given-names>K.</given-names></name></person-group><year>2010</year>. <article-title>Subcutaneous inoculation of a whole virus particle vaccine prepared from a non-pathogenic virus library induces protective immunity against H7N7 highly pathogenic avian influenza
virus in cynomolgus macaques</article-title>. <source><italic>Vaccine</italic></source><volume>28</volume>: <fpage>780</fpage>–<lpage>789</lpage>. doi: <pub-id pub-id-type="doi">10.1016/j.vaccine.2009.10.067</pub-id><pub-id pub-id-type="pmid">19857455</pub-id></mixed-citation></ref><ref id="r12"><label>12</label><mixed-citation publication-type="journal"><person-group><name><surname>Itoh</surname><given-names>Y.</given-names></name><name><surname>Ozaki</surname><given-names>H.</given-names></name><name><surname>Tsuchiya</surname><given-names>H.</given-names></name><name><surname>Okamoto</surname><given-names>K.</given-names></name><name><surname>Torii</surname><given-names>R.</given-names></name><name><surname>Sakoda</surname><given-names>Y.</given-names></name><name><surname>Kawaoka</surname><given-names>Y.</given-names></name><name><surname>Ogasawara</surname><given-names>K.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name></person-group><year>2008</year>. <article-title>A vaccine prepared from a non-pathogenic H5N1 avian influenza virus strain confers protective immunity against highly pathogenic avian influenza virus infection in cynomolgus
macaques</article-title>. <source><italic>Vaccine</italic></source><volume>26</volume>: <fpage>562</fpage>–<lpage>572</lpage>. doi: <pub-id pub-id-type="doi">10.1016/j.vaccine.2007.11.031</pub-id><pub-id pub-id-type="pmid">18164788</pub-id></mixed-citation></ref><ref id="r13"><label>13</label><mixed-citation publication-type="journal"><person-group><name><surname>Jones</surname><given-names>J. C.</given-names></name><name><surname>Baranovich</surname><given-names>T.</given-names></name><name><surname>Marathe</surname><given-names>B. M.</given-names></name><name><surname>Danner</surname><given-names>A. F.</given-names></name><name><surname>Seiler</surname><given-names>J. P.</given-names></name><name><surname>Franks</surname><given-names>J.</given-names></name><name><surname>Govorkova</surname><given-names>E. A.</given-names></name><name><surname>Krauss</surname><given-names>S.</given-names></name><name><surname>Webster</surname><given-names>R. G.</given-names></name></person-group><year>2014</year>. <article-title>Risk assessment of H2N2 influenza viruses from the avian reservoir</article-title>. <source><italic>J. Virol.</italic></source><volume>88</volume>:
<fpage>1175</fpage>–<lpage>1188</lpage>. doi: <pub-id pub-id-type="doi">10.1128/JVI.02526-13</pub-id><pub-id pub-id-type="pmid">24227848</pub-id></mixed-citation></ref><ref id="r14"><label>14</label><mixed-citation publication-type="journal"><person-group><name><surname>Kaverin</surname><given-names>N. V.</given-names></name><name><surname>Smirnov</surname><given-names>Y. A.</given-names></name><name><surname>Govorkova</surname><given-names>E. A.</given-names></name><name><surname>Rudneva</surname><given-names>I. A.</given-names></name><name><surname>Gitelman</surname><given-names>A. K.</given-names></name><name><surname>Lipatov</surname><given-names>A. S.</given-names></name><name><surname>Varich</surname><given-names>N. L.</given-names></name><name><surname>Yamnikova</surname><given-names>S. S.</given-names></name><name><surname>Makarova</surname><given-names>N. V.</given-names></name><name><surname>Webster</surname><given-names>R. G.</given-names></name><name><surname>Lvov</surname><given-names>D. K.</given-names></name></person-group><year>2000</year>. <article-title>Cross-protection and reassortment studies with avian H2 influenza viruses</article-title>. <source><italic>Arch. Virol.</italic></source><volume>145</volume>:
<fpage>1059</fpage>–<lpage>1066</lpage>. doi: <pub-id pub-id-type="doi">10.1007/s007050070109</pub-id><pub-id pub-id-type="pmid">10948982</pub-id></mixed-citation></ref><ref id="r15"><label>15</label><mixed-citation publication-type="journal"><person-group><name><surname>Kida</surname><given-names>H.</given-names></name><name><surname>Brown</surname><given-names>L. E.</given-names></name><name><surname>Webster</surname><given-names>R. G.</given-names></name></person-group><year>1982</year>. <article-title>Biological activity of monoclonal antibodies to operationally defined antigenic regions on the hemagglutinin molecule of A/Seal/Massachusetts/1/80 (H7N7) influenza
virus</article-title>. <source><italic>Virology</italic></source><volume>122</volume>: <fpage>38</fpage>–<lpage>47</lpage>. doi: <pub-id pub-id-type="doi">10.1016/0042-6822(82)90375-0</pub-id><pub-id pub-id-type="pmid">6182687</pub-id></mixed-citation></ref><ref id="r16"><label>16</label><mixed-citation publication-type="journal"><person-group><name><surname>Kishida</surname><given-names>N.</given-names></name><name><surname>Sakoda</surname><given-names>Y.</given-names></name><name><surname>Shiromoto</surname><given-names>M.</given-names></name><name><surname>Bai</surname><given-names>G. R.</given-names></name><name><surname>Isoda</surname><given-names>N.</given-names></name><name><surname>Takada</surname><given-names>A.</given-names></name><name><surname>Laver</surname><given-names>G.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name></person-group><year>2008</year>. <article-title>H2N5 influenza virus isolates from terns in Australia: genetic reassortants between those of the Eurasian and American lineages</article-title>. <source><italic>Virus
Genes</italic></source><volume>37</volume>: <fpage>16</fpage>–<lpage>21</lpage>. doi: <pub-id pub-id-type="doi">10.1007/s11262-008-0235-z</pub-id><pub-id pub-id-type="pmid">18454312</pub-id></mixed-citation></ref><ref id="r17"><label>17</label><mixed-citation publication-type="journal"><person-group><name><surname>Krauss</surname><given-names>S.</given-names></name><name><surname>Obert</surname><given-names>C. A.</given-names></name><name><surname>Franks</surname><given-names>J.</given-names></name><name><surname>Walker</surname><given-names>D.</given-names></name><name><surname>Jones</surname><given-names>K.</given-names></name><name><surname>Seiler</surname><given-names>P.</given-names></name><name><surname>Niles</surname><given-names>L.</given-names></name><name><surname>Pryor</surname><given-names>S. P.</given-names></name><name><surname>Obenauer</surname><given-names>J. C.</given-names></name><name><surname>Naeve</surname><given-names>C. W.</given-names></name><name><surname>Widjaja</surname><given-names>L.</given-names></name><name><surname>Webby</surname><given-names>R. J.</given-names></name><name><surname>Webster</surname><given-names>R. G.</given-names></name></person-group><year>2007</year>. <article-title>Influenza in migratory birds and evidence of limited intercontinental virus exchange</article-title>. <source><italic>PLoS Pathog.</italic></source><volume>3</volume>:
<fpage>e167</fpage>. doi: <pub-id pub-id-type="doi">10.1371/journal.ppat.0030167</pub-id><pub-id pub-id-type="pmid">17997603</pub-id></mixed-citation></ref><ref id="r18"><label>18</label><mixed-citation publication-type="journal"><person-group><name><surname>Lenny</surname><given-names>B. J.</given-names></name><name><surname>Sonnberg</surname><given-names>S.</given-names></name><name><surname>Danner</surname><given-names>A. F.</given-names></name><name><surname>Friedman</surname><given-names>K.</given-names></name><name><surname>Webby</surname><given-names>R. J.</given-names></name><name><surname>Webster</surname><given-names>R. G.</given-names></name><name><surname>Jones</surname><given-names>J. C.</given-names></name></person-group><year>2017</year>. <article-title>Evaluation of multivalent H2 influenza pandemic vaccines in mice</article-title>. <source><italic>Vaccine</italic></source><volume>35</volume>:
<fpage>1455</fpage>–<lpage>1463</lpage>. doi: <pub-id pub-id-type="doi">10.1016/j.vaccine.2017.01.026</pub-id><pub-id pub-id-type="pmid">28189402</pub-id></mixed-citation></ref><ref id="r19"><label>19</label><mixed-citation publication-type="journal"><person-group><name><surname>Ma</surname><given-names>W.</given-names></name><name><surname>Vincent</surname><given-names>A. L.</given-names></name><name><surname>Gramer</surname><given-names>M. R.</given-names></name><name><surname>Brockwell</surname><given-names>C. B.</given-names></name><name><surname>Lager</surname><given-names>K. M.</given-names></name><name><surname>Janke</surname><given-names>B. H.</given-names></name><name><surname>Gauger</surname><given-names>P. C.</given-names></name><name><surname>Patnayak</surname><given-names>D. P.</given-names></name><name><surname>Webby</surname><given-names>R. J.</given-names></name><name><surname>Richt</surname><given-names>J. A.</given-names></name></person-group><year>2007</year>. <article-title>Identification of H2N3 influenza A viruses from swine in the United States</article-title>. <source><italic>Proc. Natl. Acad. Sci. U.S.A.</italic></source><volume>104</volume>:
<fpage>20949</fpage>–<lpage>20954</lpage>. doi: <pub-id pub-id-type="doi">10.1073/pnas.0710286104</pub-id><pub-id pub-id-type="pmid">18093945</pub-id></mixed-citation></ref><ref id="r20"><label>20</label><mixed-citation publication-type="journal"><person-group><name><surname>Nabel</surname><given-names>G. J.</given-names></name><name><surname>Wei</surname><given-names>C. J.</given-names></name><name><surname>Ledgerwood</surname><given-names>J. E.</given-names></name></person-group><year>2011</year>. <article-title>Vaccinate for the next H2N2 pandemic now</article-title>. <source><italic>Nature</italic></source><volume>471</volume>: <fpage>157</fpage>–<lpage>158</lpage>. doi: <pub-id pub-id-type="doi">10.1038/471157a</pub-id><pub-id pub-id-type="pmid">21390107</pub-id></mixed-citation></ref><ref id="r21"><label>21</label><mixed-citation publication-type="journal"><person-group><name><surname>Nishi</surname><given-names>T.</given-names></name><name><surname>Sakoda</surname><given-names>Y.</given-names></name><name><surname>Okamatsu</surname><given-names>M.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name></person-group><year>2014</year>. <article-title>Potency of an inactivated influenza vaccine prepared from A/duck/Hong Kong/960/1980 (H6N2) against a challenge with A/duck/Vietnam/OIE-0033/2012 (H6N2) in mice</article-title>.
<source><italic>Arch. Virol.</italic></source><volume>159</volume>: <fpage>2567</fpage>–<lpage>2574</lpage>. doi: <pub-id pub-id-type="doi">10.1007/s00705-014-2107-2</pub-id><pub-id pub-id-type="pmid">24824346</pub-id></mixed-citation></ref><ref id="r22"><label>22</label><mixed-citation publication-type="journal"><person-group><name><surname>Nomura</surname><given-names>N.</given-names></name><name><surname>Sakoda</surname><given-names>Y.</given-names></name><name><surname>Soda</surname><given-names>K.</given-names></name><name><surname>Okamatsu</surname><given-names>M.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name></person-group><year>2012</year>. <article-title>An H9N2 influenza virus vaccine prepared from a non-pathogenic isolate from a migratory duck confers protective immunity in mice against challenge with an H9N2 virus isolated from a
girl in Hong Kong</article-title>. <source><italic>J. Vet. Med. Sci.</italic></source><volume>74</volume>: <fpage>441</fpage>–<lpage>447</lpage>. doi: <pub-id pub-id-type="doi">10.1292/jvms.11-0471</pub-id><pub-id pub-id-type="pmid">22123308</pub-id></mixed-citation></ref><ref id="r23"><label>23</label><mixed-citation publication-type="journal"><person-group><name><surname>Okamatsu</surname><given-names>M.</given-names></name><name><surname>Sakoda</surname><given-names>Y.</given-names></name><name><surname>Hiono</surname><given-names>T.</given-names></name><name><surname>Yamamoto</surname><given-names>N.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name></person-group><year>2013</year>. <article-title>Potency of a vaccine prepared from A/swine/Hokkaido/2/1981 (H1N1) against A/Narita/1/2009 (H1N1) pandemic influenza virus strain</article-title>. <source><italic>Virol.
J.</italic></source><volume>10</volume>: <fpage>47</fpage>. doi: <pub-id pub-id-type="doi">10.1186/1743-422X-10-47</pub-id><pub-id pub-id-type="pmid">23384324</pub-id></mixed-citation></ref><ref id="r24"><label>24</label><mixed-citation publication-type="journal"><person-group><name><surname>Piaggio</surname><given-names>A. J.</given-names></name><name><surname>Shriner</surname><given-names>S. A.</given-names></name><name><surname>VanDalen</surname><given-names>K. K.</given-names></name><name><surname>Franklin</surname><given-names>A. B.</given-names></name><name><surname>Anderson</surname><given-names>T. D.</given-names></name><name><surname>Kolokotronis</surname><given-names>S. O.</given-names></name></person-group><year>2012</year>. <article-title>Molecular surveillance of low pathogenic avian influenza viruses in wild birds across the United States: inferences from the hemagglutinin gene</article-title>. <source><italic>PLOS
ONE</italic></source><volume>7</volume>: <fpage>e50834</fpage>. doi: <pub-id pub-id-type="doi">10.1371/journal.pone.0050834</pub-id><pub-id pub-id-type="pmid">23226543</pub-id></mixed-citation></ref><ref id="r25"><label>25</label><mixed-citation publication-type="journal"><person-group><name><surname>Sakabe</surname><given-names>S.</given-names></name><name><surname>Sakoda</surname><given-names>Y.</given-names></name><name><surname>Haraguchi</surname><given-names>Y.</given-names></name><name><surname>Isoda</surname><given-names>N.</given-names></name><name><surname>Soda</surname><given-names>K.</given-names></name><name><surname>Takakuwa</surname><given-names>H.</given-names></name><name><surname>Saijo</surname><given-names>K.</given-names></name><name><surname>Sawata</surname><given-names>A.</given-names></name><name><surname>Kume</surname><given-names>K.</given-names></name><name><surname>Hagiwara</surname><given-names>J.</given-names></name><name><surname>Tuchiya</surname><given-names>K.</given-names></name><name><surname>Lin</surname><given-names>Z.</given-names></name><name><surname>Sakamoto</surname><given-names>R.</given-names></name><name><surname>Imamura</surname><given-names>T.</given-names></name><name><surname>Sasaki</surname><given-names>T.</given-names></name><name><surname>Kokumai</surname><given-names>N.</given-names></name><name><surname>Kawaoka</surname><given-names>Y.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name></person-group><year>2008</year>. <article-title>A vaccine prepared from a non-pathogenic H7N7 virus isolated from natural reservoir conferred protective immunity against the challenge with lethal dose of highly pathogenic avian
influenza virus in chickens</article-title>. <source><italic>Vaccine</italic></source><volume>26</volume>: <fpage>2127</fpage>–<lpage>2134</lpage>. doi: <pub-id pub-id-type="doi">10.1016/j.vaccine.2008.02.001</pub-id><pub-id pub-id-type="pmid">18346824</pub-id></mixed-citation></ref><ref id="r26"><label>26</label><mixed-citation publication-type="journal"><person-group><name><surname>Schäfer</surname><given-names>J. R.</given-names></name><name><surname>Kawaoka</surname><given-names>Y.</given-names></name><name><surname>Bean</surname><given-names>W. J.</given-names></name><name><surname>Süss</surname><given-names>J.</given-names></name><name><surname>Senne</surname><given-names>D.</given-names></name><name><surname>Webster</surname><given-names>R. G.</given-names></name></person-group><year>1993</year>. <article-title>Origin of the pandemic 1957 H2 influenza A virus and the persistence of its possible progenitors in the avian reservoir</article-title>.
<source><italic>Virology</italic></source><volume>194</volume>: <fpage>781</fpage>–<lpage>788</lpage>. doi: <pub-id pub-id-type="doi">10.1006/viro.1993.1319</pub-id><pub-id pub-id-type="pmid">7684877</pub-id></mixed-citation></ref><ref id="r27"><label>27</label><mixed-citation publication-type="journal"><person-group><name><surname>Simonsen</surname><given-names>L.</given-names></name><name><surname>Clarke</surname><given-names>M. J.</given-names></name><name><surname>Schonberger</surname><given-names>L. B.</given-names></name><name><surname>Arden</surname><given-names>N. H.</given-names></name><name><surname>Cox</surname><given-names>N. J.</given-names></name><name><surname>Fukuda</surname><given-names>K.</given-names></name></person-group><year>1998</year>. <article-title>Pandemic versus epidemic influenza mortality: a pattern of changing age distribution</article-title>. <source><italic>J. Infect. Dis.</italic></source><volume>178</volume>:
<fpage>53</fpage>–<lpage>60</lpage>. doi: <pub-id pub-id-type="doi">10.1086/515616</pub-id><pub-id pub-id-type="pmid">9652423</pub-id></mixed-citation></ref><ref id="r28"><label>28</label><mixed-citation publication-type="journal"><person-group><name><surname>Wu</surname><given-names>H.</given-names></name><name><surname>Peng</surname><given-names>X.</given-names></name><name><surname>Peng</surname><given-names>X.</given-names></name><name><surname>Cheng</surname><given-names>L.</given-names></name><name><surname>Wu</surname><given-names>N.</given-names></name></person-group><year>2016</year>. <article-title>Genetic and molecular characterization of a novel reassortant H2N8 subtype avian influenza virus isolated from a domestic duck in Zhejiang Province in China</article-title>.
<source><italic>Virus Genes</italic></source><volume>52</volume>: <fpage>863</fpage>–<lpage>866</lpage>. doi: <pub-id pub-id-type="doi">10.1007/s11262-016-1368-0</pub-id><pub-id pub-id-type="pmid">27379842</pub-id></mixed-citation></ref><ref id="r29"><label>29</label><mixed-citation publication-type="journal"><person-group><name><surname>Yamamoto</surname><given-names>N.</given-names></name><name><surname>Sakoda</surname><given-names>Y.</given-names></name><name><surname>Motoshima</surname><given-names>M.</given-names></name><name><surname>Yoshino</surname><given-names>F.</given-names></name><name><surname>Soda</surname><given-names>K.</given-names></name><name><surname>Okamatsu</surname><given-names>M.</given-names></name><name><surname>Kida</surname><given-names>H.</given-names></name></person-group><year>2011</year>. <article-title>Characterization of a non-pathogenic H5N1 influenza virus isolated from a migratory duck flying from Siberia in Hokkaido, Japan, in October 2009</article-title>.
<source><italic>Virol. J.</italic></source><volume>8</volume>: <fpage>65</fpage>. doi: <pub-id pub-id-type="doi">10.1186/1743-422X-8-65</pub-id><pub-id pub-id-type="pmid">21310090</pub-id></mixed-citation></ref></ref-list></back></pmc></record>Pour manipuler ce document sous Unix (Dilib)
EXPLOR_STEP=$WICRI_ROOT/Sante/explor/H2N2V1/Data/Pmc/Corpus
HfdSelect -h $EXPLOR_STEP/biblio.hfd -nk 000A18 | SxmlIndent | more
Ou
HfdSelect -h $EXPLOR_AREA/Data/Pmc/Corpus/biblio.hfd -nk 000A18 | SxmlIndent | more
Pour mettre un lien sur cette page dans le réseau Wicri
{{Explor lien
|wiki= Sante
|area= H2N2V1
|flux= Pmc
|étape= Corpus
|type= RBID
|clé= PMC:5709558
|texte= Potency of an inactivated influenza vaccine prepared from A/duck/Hokkaido/162/2013 (H2N1) against a challenge with A/swine/Missouri/2124514/2006 (H2N3) in mice
}}
Pour générer des pages wiki
HfdIndexSelect -h $EXPLOR_AREA/Data/Pmc/Corpus/RBID.i -Sk "pubmed:28993601" \
| HfdSelect -Kh $EXPLOR_AREA/Data/Pmc/Corpus/biblio.hfd \
| NlmPubMed2Wicri -a H2N2V1
| This area was generated with Dilib version V0.6.33. |  |