Antibodies to influenza viruses (including the human A2-Asian-57 strain) in sera from Australian shearwaters (Puffinus pacificus)

Sera were collected from 320 shearwaters (Puffinus pacificus chlororhynchus) nesting on two islands off the east coast of northern Australia in December 1969. About 10% of these sera specifically inhibited the neuraminidase of the 1957 strain of human influenza (A2/Asian/57), some to high titre.