Further studies of the antigenic properties of H3N2 strains of influenza A isolated from swine in South East Asia.
H3N2 strains of influenza A isolated from swine in Hong Kong were compared with human strains of H3N2 influenza A variants in reciprocal HI tests using ferret sera. One isolate from swine was indistinguishable from A/Hong Kong/68, one set of viruses isolated in 1976 and 1977 was most related to A/Hong Kong/68 but was not identical to it, two isolates from 1976 were 'bridging strains' that cross-reacted equally with the contemporary variants A/Victoria/3/75 and A/Texas/1/77, similarly to a small number of recent human isolates, and two isolates from 1977 were similar to A/Victoria/3/75. These general relationships were supported by neuraminidase inhibition tests. The findings confirm and extend previous results indicating that swine may be a reservoir of old and novel variants of influenza A H3N2 strains related to those that infect man.
D000818:Animals; D000956:Antigens, Viral / Q000032:analysis*; D003429:Cross Reactions; D004197:Disease Reservoirs; D000939:Epitopes; D006385:Hemagglutination Inhibition Tests; D006723:Hong Kong; D053122:Influenza A Virus, H3N2 Subtype; D009980:Influenza A virus / Q000276:immunology*; D013552:Swine / Q000382:microbiology*; D014132:Trachea / Q000382:microbiology
D000956:Antigens, Viral; D000939:Epitopes