• 1 January 1979
    • journal article
    • research article
    • Vol. 244  (2-3) , 135-143
Abstract
Three influenza A viruses possessing hemagglutinin-Hav7 and neuraminidase-N2 were isolated from 20 wild free-flying ducks in Hokkaido, Japan in autumn, 1977. The neuraminidase antigen of these viruses cross-reacted with the Asian influenza virus (H2 N2) but reacted scarecely with the Hong Kong strain (H3 N2) in cross neuraminidase-inhibition tests.