The antigenicity of the haemagglutinin (HA) of the influenza A viruses of swine (IAV-S) plays a crucial role in determining vaccine efficacy in pigs. In addition, the antigenic difference between the IAV-S and human seasonal vaccine strains has been considered as one of the risk factors for human infection with IAV-S. However, the antigenicity of the IAV-S currently circulating in Japan and Vietnam has not been studied well. We therefore characterized the antigenicity of the recent H1 IAV-S and H3 IAV-S isolated from Japanese and Vietnamese pigs by using a haemagglutination inhibition (HI) assay. The recent Japanese H1N2 SIVs were antigenically different from the domestic H1N1 IAV-S, contemporary human H1 vaccine strains, and those isolated in Vietnam. The antigenicity of the H3N2 IAV-S isolated in Japan also differed from that of domestic H3N2 IAV-S and contemporary human H3 vaccine strains, as well as that of strains isolated in Vietnam. To our knowledge, this study is the first to elucidate the antigenic variations of the IAV-S currently circulating in both countries, and suggests that monitoring the antigenicity of IAV-S could contribute not only to the selection of the optimal strains for IAV-S but also to public health.
(Influenza and Prion Disease Research Center)
References:
Takemae N. et al (2013) Arch Virol 158 (4):859-876 (Doi:10.1007/s0075-013-1616-8)
