SIV vaccine induced neutralizing and hemagglutination inhibition antibodies

摘要

Swine influenza virus (SIV) is a type A influenza virus which manifests itself clinically in pigs as respiratory disease accompanied by high fever. The major antigenic determinants of SIV include the viral surface glycopro-teins, hemagglutinin (HA) and neuraminidase (NA). The appearance of antigenic drift and shift involving genetic reassortment of the genes for HA and/or NA permits the virus to escape the host immune response. Until 1997, essentially one subtype of SIV, classical H1N1, was circulating in the US swine population. Since then, additional genetic subtypes and variants have emerged including a reassortant H1N1 that is a result of antigenic shift of genetic material between the H3N2 and H1N1 subtypes. Vaccines for both H1N1 alone and combined with H3N2 are currently available commercially. Although research shows a 94-96% sequence homology between H1N1 isolates of SIV, questions about cross protection between isolates in the field are common.