| 117 | Humans |
| 84 | Animals |
| 75 | Coronavirus Infections |
| 48 | Female |
| 40 | Male |
| 31 | Pneumonia, Viral |
| 25 | SARS Virus |
| 23 | Adult |
| 22 | Antibodies, Viral |
| 21 | Severe Acute Respiratory Syndrome |
| 21 | China |
| 20 | Betacoronavirus |
| 19 | Middle East Respiratory Syndrome Coronavirus |
| 19 | Middle Aged |
| 18 | Disease Outbreaks |
| 17 | Coronavirus |
| 16 | Cattle |
| 16 | Aged |
| 15 | Mice |
| 14 | Virus Diseases |
| 14 | Respiratory Tract Infections |
| 14 | Coronaviridae |
| 14 | Antiviral Agents |
| 13 | Child |
| 13 | Child, Preschool |
| 12 | Viral Proteins |
| 12 | Cattle Diseases |
| 12 | Adolescent |
| 11 | Young Adult |
| 11 | Infant |
| 11 | Coronaviridae Infections |
| 10 | Saudi Arabia |
| 9 | Virus Replication |
| 9 | Viral Envelope Proteins |
| 9 | Rats |
| 9 | Polymerase Chain Reaction |
| 9 | Infant, Newborn |
| 9 | Antigens, Viral |
| 8 | Time Factors |
| 8 | Swine |
| 8 | Molecular Sequence Data |
| 8 | Lung |
| 8 | Global Health |
| 8 | Genome, Viral |
| 7 | Viruses |
| 7 | Retrospective Studies |
| 7 | Radiography, Thoracic |
| 7 | RNA, Viral |
| 7 | Phylogeny |
| 7 | Peptides |
| 7 | Pandemics |
| 7 | Murine hepatitis virus |
| 7 | Membrane Glycoproteins |
| 7 | Enzyme-Linked Immunosorbent Assay |
| 7 | Cell Line |
| 7 | Amino Acid Sequence |
| 6 | Transmissible gastroenteritis virus |
| 6 | Tomography, X-Ray Computed |
| 6 | Structure-Activity Relationship |
| 6 | Spike Glycoprotein, Coronavirus |
| 6 | Species Specificity |
| 6 | Respiratory Syncytial Virus Infections |
| 6 | Pneumonia |
| 6 | Host-Pathogen Interactions |
| 6 | Coronavirus, Bovine |
| 6 | Cats |
| 6 | Aged, 80 and over |
| 5 | Zoonoses |
| 5 | World Health Organization |
| 5 | Viral Vaccines |
| 5 | Swine Diseases |
| 5 | Sweden |
| 5 | Sequence Alignment |
| 5 | Sensitivity and Specificity |
| 5 | Reverse Transcriptase Polymerase Chain Reaction |
| 5 | Respiratory Syncytial Viruses |
| 5 | Recombinant Proteins |
| 5 | Protein Binding |
| 5 | Prognosis |
| 5 | Prevalence |
| 5 | Neutralization Tests |
| 5 | Influenza, Human |
| 5 | Fluorescent Antibody Technique |
| 5 | Feces |
| 5 | Dogs |
| 5 | DNA, Viral |
| 5 | Cross-Sectional Studies |
| 5 | Computational Biology |
| 5 | Bacterial Infections |
| 5 | Antibodies, Bacterial |
| 5 | Age Factors |
| 4 | Virus Cultivation |
| 4 | United States |
| 4 | Travel |
| 4 | T-Lymphocytes, Cytotoxic |
| 4 | Serologic Tests |
| 4 | Seroepidemiologic Studies |
| 4 | Risk Factors |
| 4 | Respiratory Tract Diseases |
| 4 | Republic of Korea |
| 4 | RNA Viruses |
| 4 | Protein Structure, Secondary |
| 4 | Poultry Diseases |
| 4 | Population Surveillance |
| 4 | Paramyxoviridae Infections |
| 4 | Mice, Inbred BALB C |
| 4 | Infectious bronchitis virus |
| 4 | Hemagglutination Inhibition Tests |
| 4 | Encephalomyelitis |
| 4 | Disease Reservoirs |
| 4 | Demyelinating Diseases |
| 4 | Contact Tracing |
| 4 | Cluster Analysis |
| 4 | Chickens |
| 4 | Camelus |
| 4 | Bronchoalveolar Lavage Fluid |
| 4 | Brain |
| 4 | Base Sequence |
| 4 | Animals, Newborn |
| 4 | Acute Disease |
| 3 | Viral Structural Proteins |
| 3 | Viral Fusion Proteins |
| 3 | Vero Cells |
| 3 | Trachea |
| 3 | Surveys and Questionnaires |
| 3 | Specimen Handling |
| 3 | Reproducibility of Results |
| 3 | Rabbits |
| 3 | Public Health |
| 3 | Pregnancy |
| 3 | Practice Guidelines as Topic |
| 3 | Peptidyl-Dipeptidase A |
| 3 | Orthomyxoviridae |
| 3 | Open Reading Frames |
| 3 | Mycoplasma Infections |
| 3 | Molecular Dynamics Simulation |
| 3 | Models, Molecular |
| 3 | Middle East |
| 3 | Microscopy, Electron |
| 3 | Mice, Inbred C57BL |
| 3 | Magnetic Resonance Spectroscopy |
| 3 | Macrophages |
| 3 | Lung Diseases |
| 3 | Interferon Type I |
| 3 | Incidence |
| 3 | Immunoglobulin G |
| 3 | Hospitalization |
| 3 | Hemagglutinins, Viral |
| 3 | Health Planning |
| 3 | Genes, Viral |
| 3 | Fever |
| 3 | Fatal Outcome |
| 3 | Escherichia coli |
| 3 | Epitopes |
| 3 | Enterocolitis, Pseudomembranous |
| 3 | Drug Design |
| 3 | Diarrhea |
| 3 | Diagnosis, Differential |
| 3 | Cytopathogenic Effect, Viral |
| 3 | Cough |
| 3 | Circular Dichroism |
| 3 | Chlorocebus aethiops |
| 3 | Cat Diseases |
| 3 | Biosensing Techniques |
| 3 | Biomarkers |
| 3 | Bacteria |
| 3 | Animal Husbandry |
| 2 | Virus Physiological Phenomena |
| 2 | Virulence |
| 2 | Viral Load |
| 2 | Vaccines, Synthetic |
| 2 | Vaccines, DNA |
| 2 | United Kingdom |
| 2 | Trypsin |
| 2 | Travel-Related Illness |
| 2 | Transcription, Genetic |
| 2 | Tonsillectomy |
| 2 | Toll-Like Receptor 7 |
| 2 | Tertiary Care Centers |
| 2 | T-Lymphocytes |
| 2 | Syndrome |
| 2 | Survival Rate |
| 2 | Substrate Specificity |
| 2 | Stress, Psychological |
| 2 | Spectrometry, Fluorescence |
| 2 | Signal Transduction |
| 2 | Sequence Homology, Nucleic Acid |
| 2 | Sequence Analysis, Protein |
| 2 | Sequence Analysis, DNA |
| 2 | Rotavirus Infections |
| 2 | Rodent Diseases |
| 2 | Risk |
| 2 | Rhinovirus |
| 2 | Respiratory System |
| 2 | Respiratory Syncytial Virus, Bovine |
| 2 | Respiratory Distress Syndrome, Adult |
| 2 | Reproduction |
| 2 | Recombination, Genetic |
| 2 | Real-Time Polymerase Chain Reaction |
| 2 | Reagent Kits, Diagnostic |
| 2 | Random Allocation |
| 2 | RNA Interference |
| 2 | Public Health Surveillance |
| 2 | Protein Structure, Tertiary |
| 2 | Protein Multimerization |
| 2 | Protein Folding |
| 2 | Porcine epidemic diarrhea virus |
| 2 | Politics |
| 2 | Picornaviridae Infections |
| 2 | Peritonitis |
| 2 | Periodicals as Topic |
| 2 | Peptide Fragments |
| 2 | Patient Isolation |
| 2 | Patient Care Planning |
| 2 | Palatine Tonsil |
| 2 | Orthomyxoviridae Infections |
| 2 | Nictitating Membrane |
| 2 | Nervous System Diseases |
| 2 | Mycoplasma |
| 2 | Multiplex Polymerase Chain Reaction |
| 2 | Mortality |
| 2 | Molecular Structure |
| 2 | Molecular Epidemiology |
| 2 | Models, Statistical |
| 2 | Models, Biological |
| 2 | Microbial Sensitivity Tests |
| 2 | Mice, SCID |
| 2 | Mice, Knockout |
| 2 | Metapneumovirus |
| 2 | Membrane Proteins |
| 2 | Magnetic Resonance Imaging |
| 2 | Lymphoid Tissue |
| 2 | Liver |
| 2 | Lipid Bilayers |
| 2 | Intestines |
| 2 | International Health Regulations |
| 2 | Interferon-alpha |
| 2 | Intensive Care Units |
| 2 | Information Dissemination |
| 2 | Infections |
| 2 | Infant, Newborn, Diseases |
| 2 | India |
| 2 | Immunoglobulin A |
| 2 | Immunocompetence |
| 2 | Immunity |
| 2 | Immunity, Innate |
| 2 | Hypertrophy |
| 2 | Hydrophobic and Hydrophilic Interactions |
| 2 | Housing, Animal |
| 2 | Hepacivirus |
| 2 | Hematopoietic Stem Cell Transplantation |
| 2 | Guinea Pigs |
| 2 | Genetic Vectors |
| 2 | Gene Expression Regulation |
| 2 | Gene Expression Profiling |
| 2 | France |
| 2 | Follow-Up Studies |
| 2 | Fluorescent Dyes |
| 2 | Feline Infectious Peritonitis |
| 2 | Escherichia coli Infections |
| 2 | Epitopes, T-Lymphocyte |
| 2 | Epithelial Cells |
| 2 | Enteritis |
| 2 | Drug Therapy, Combination |
| 2 | Drug Discovery |
| 2 | Dog Diseases |
| 2 | Disease Transmission, Infectious |
| 2 | Disease Progression |
| 2 | Disease Models, Animal |
| 2 | Delivery of Health Care |
| 2 | Databases, Genetic |
| 2 | Dairying |
| 2 | Cytomegalovirus |
| 2 | Cysteine Endopeptidases |
| 2 | Coronavirus, Canine |
| 2 | Conservation of Natural Resources |
| 2 | Consensus Sequence |
| 2 | Comorbidity |
| 2 | Communicable Diseases, Emerging |
| 2 | Communicable Disease Control |
| 2 | Commerce |
| 2 | Chymotrypsin |
| 2 | Chick Embryo |
| 2 | Cells, Cultured |
| 2 | Cell Survival |
| 2 | Catalytic Domain |
| 2 | Catalysis |
| 2 | Case-Control Studies |
| 2 | Body Weight |
| 2 | Birds |
| 2 | Binding Sites |
| 2 | Australia |
| 2 | Asymptomatic Infections |
| 2 | Antibodies, Monoclonal |
| 2 | Animals, Wild |
| 2 | Animals, Laboratory |
| 2 | Animal Nutritional Physiological Phenomena |
| 2 | Animal Feed |
| 2 | Algorithms |
| 2 | Albumins |
| 2 | Adenoviridae |
| 1 | Zidovudine |
| 1 | Yellow fever virus |
| 1 | Workforce |
| 1 | Whole Genome Sequencing |
| 1 | West Nile virus |
| 1 | West Nile Fever |
| 1 | Weight Gain |
| 1 | Water-Electrolyte Balance |
| 1 | Virus Internalization |
| 1 | Virology |
| 1 | Virion |
| 1 | Viral Nonstructural Proteins |
| 1 | Viral Matrix Proteins |
| 1 | Vaccines |
| 1 | Ureaplasma |
| 1 | Ureaplasma Infections |
| 1 | Universal Precautions |
| 1 | United Arab Emirates |
| 1 | Unilamellar Liposomes |
| 1 | Uncertainty |
| 1 | Turkeys |
| 1 | Turkey |
| 1 | Tumor Necrosis Factor-alpha |
| 1 | Transportation |
| 1 | Transplantation, Heterologous |
| 1 | Transfection |
| 1 | Transcriptome |
| 1 | Toxoplasmosis, Animal |
| 1 | Tonsillitis |
| 1 | Toll-Like Receptor 3 |
| 1 | Togaviridae Infections |
| 1 | Time-to-Treatment |
| 1 | Tigers |
| 1 | Ticks |
| 1 | Thyroid Gland |
| 1 | Thoracic Surgical Procedures |
| 1 | Thermodynamics |
| 1 | Th1 Cells |
| 1 | Temperature |
| 1 | Taq Polymerase |
| 1 | Taiwan |
| 1 | THP-1 Cells |
| 1 | TATA-Box Binding Protein |
| 1 | Switzerland |
| 1 | Sus scrofa |
| 1 | Surface Properties |
| 1 | Surface Plasmon Resonance |
| 1 | State Medicine |
| 1 | Spleen |
| 1 | Spinal Cord |
| 1 | Spectrophotometry, Infrared |
| 1 | Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization |
| 1 | Soybeans |
| 1 | Software |
| 1 | Sodium |
| 1 | Sodium Dodecyl Sulfate |
| 1 | Social Support |
| 1 | Smallpox |
| 1 | Sleep |
| 1 | Sleep Apnea, Obstructive |
| 1 | Sleep Apnea Syndromes |
| 1 | Singapore |
| 1 | Simplexvirus |
| 1 | Sigmodontinae |
| 1 | Shock |
| 1 | Shiga Toxin 1 |
| 1 | Sheep |
| 1 | Sheep Diseases |
| 1 | Sex Characteristics |
| 1 | Severity of Illness Index |
| 1 | Serum Amyloid A Protein |
| 1 | Sequence Homology |
| 1 | Sequence Homology, Amino Acid |
| 1 | Self Efficacy |
| 1 | Schiff Bases |
| 1 | Russia |
| 1 | Rotavirus |
| 1 | Ritonavir |
| 1 | Riboswitch |
| 1 | Ribose |
| 1 | Ribose-Phosphate Pyrophosphokinase |
| 1 | Ribonucleotides |
| 1 | Ribavirin |
| 1 | Rhinitis |
| 1 | Response Elements |
| 1 | Respirovirus Infections |
| 1 | Respiratory Mucosa |
| 1 | Respiratory Insufficiency |
| 1 | Respiratory Hypersensitivity |
| 1 | Respiration, Artificial |
| 1 | Research |
| 1 | Renin-Angiotensin System |
| 1 | Reference Values |
| 1 | Reference Standards |
| 1 | Rectal Neoplasms |
| 1 | Recombinant Fusion Proteins |
| 1 | Receptors, Virus |
| 1 | Receptors, IgG |
| 1 | Rats, Nude |
| 1 | Rats, Inbred Strains |
| 1 | Radiography |
| 1 | RNA, Small Interfering |
| 1 | RNA, Messenger |
| 1 | RNA Virus Infections |
| 1 | Quinazolinones |
| 1 | Quinazolines |
| 1 | Quantum Theory |
| 1 | Qatar |
| 1 | Pyrazolones |
| 1 | Pyrazines |
| 1 | Purpura, Schoenlein-Henoch |
| 1 | Pulmonary Disease, Chronic Obstructive |
| 1 | Publications |
| 1 | Public Health Practice |
| 1 | Public Health Administration |
| 1 | Proteomics |
| 1 | Proteolysis |
| 1 | Proteins |
| 1 | Protein Sorting Signals |
| 1 | Protein Processing, Post-Translational |
| 1 | Protein Isoforms |
| 1 | Protein Interaction Domains and Motifs |
| 1 | Protein Denaturation |
| 1 | Protein Conformation |
| 1 | Protein Biosynthesis |
| 1 | Protein Array Analysis |
| 1 | Protective Clothing |
| 1 | Protease Inhibitors |
| 1 | Prospective Studies |
| 1 | Probiotics |
| 1 | Primary Health Care |
| 1 | Predictive Value of Tests |
| 1 | Poxviridae |
| 1 | Poxviridae Infections |
| 1 | Potassium |
| 1 | Porcine respiratory and reproductive syndrome virus |
| 1 | Population Density |
| 1 | Pons |
| 1 | Polygonum |
| 1 | Polyethylene Glycols |
| 1 | Pneumonia, Mycoplasma |
| 1 | Plasma Cells |
| 1 | Piperazines |
| 1 | Piperazine |
| 1 | Phthalic Anhydrides |
| 1 | Phosphotransferases (Alcohol Group Acceptor) |
| 1 | Phosphorylcholine |
| 1 | Pharmaceutical Preparations |
| 1 | Pestivirus |
| 1 | Permeability |
| 1 | Peptidylprolyl Isomerase |
| 1 | Peptide Hydrolases |
| 1 | Peptide Chain Initiation, Translational |
| 1 | Pepsin A |
| 1 | Pentosyltransferases |
| 1 | Pediatrics |
| 1 | Patient Care |
| 1 | Pasteurella multocida |
| 1 | Pasteurella Infections |
| 1 | Particle Size |
| 1 | Paris |
| 1 | Paramyxoviridae |
| 1 | Paralysis |
| 1 | Parainfluenza Virus 3, Human |
| 1 | Parainfluenza Virus 1, Human |
| 1 | Panama |
| 1 | Pakistan |
| 1 | PPAR gamma |
| 1 | Oxidation-Reduction |
| 1 | Oxadiazoles |
| 1 | Outcome Assessment, Health Care |
| 1 | Organelles |
| 1 | Organ Specificity |
| 1 | Optic Chiasm |
| 1 | Oligopeptides |
| 1 | Oligodeoxyribonucleotides |
| 1 | Olfactory Nerve Diseases |
| 1 | Olfaction Disorders |
| 1 | Odds Ratio |
| 1 | Nutritional Support |
| 1 | Nurse Midwives |
| 1 | Nucleotides |
| 1 | Nucleosides |
| 1 | Nucleic Acid Amplification Techniques |
| 1 | Nuclear Magnetic Resonance, Biomolecular |
| 1 | Norway |
| 1 | Nitric Oxide |
| 1 | Neutrophils |
| 1 | Neutrophil Infiltration |
| 1 | Neutral Red |
| 1 | Neurons |
| 1 | Neuroimaging |
| 1 | Neural Networks, Computer |
| 1 | Neprilysin |
| 1 | Nasopharynx |
| 1 | Nasal Mucosa |
| 1 | Nasal Cavity |
| 1 | Nasal Bone |
| 1 | Myocarditis |
