1. Immunity to Influenza A H9N2 Viruses Induced by Infection and Vaccination
- Author
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Gloria D. Kelly, Terrence M. Tumpey, Jean Hu-Primmer, Mary Renshaw, Jacqueline M. Katz, and Xiuhua Lu
- Subjects
viruses ,Immunology ,Cross Reactions ,Biology ,Virus Replication ,medicine.disease_cause ,Microbiology ,H5N1 genetic structure ,Virus ,Mice ,Immunity ,Virology ,Influenza, Human ,Influenza A Virus, H9N2 Subtype ,medicine ,Influenza A virus ,Animals ,Humans ,Mice, Inbred BALB C ,Hemagglutination assay ,Vaccination ,Influenza A virus subtype H5N1 ,Disease Models, Animal ,Vaccines, Inactivated ,Viral replication ,Influenza Vaccines ,Insect Science ,Pathogenesis and Immunity ,Female - Abstract
Avian influenza A H9N2 viruses are widespread among domestic poultry and were recently isolated from humans with respiratory illness in China. Two antigenically and genetically distinct groups of H9N2 viruses (G1 and G9) are prevalent in China. To evaluate a strategy for vaccination, we compared G1 and G9 viruses for their relative immunogenicity and cross-protective efficacy. Infection of BALB/c mice with representative viruses of either group protected against subsequent challenge with the homologous or heterologous H9N2 virus in the absence of detectable cross-reactive serum hemagglutination inhibition antibody. Mice injected intramuscularly with inactivated G1 whole virus vaccine were completely protected from challenge with either H9N2 virus. In contrast, mice administered inactivated G9 vaccine were only partially protected against heterologous challenge with the G1 virus. These results have implications for the development of human vaccines against H9N2 viruses, a priority for pandemic preparedness.
- Published
- 2001