Serological cross-reactions were detected between four avian influenza viruses and a human A 2/57 virus and between an avian (TURKEY/CANADA/63) and an equine (EQUI 2/MIAMI/63) strain. The reactions were detected by strain-specific complement fixation tests and neuraminidase inhibition but not by haemagglutination-inhibition. Specific antiserum to the neuraminidase of an A 2/57 virus also reacted with the four avian viruses showing that it was the neuraminidase antigen on the avian and human A 2 virus that were antigenically closely related. The possibility that these viruses may have arisen by recombination between human and avian influenza viruses in nature is discussed.
AdaG. L.,
LindP. E.,
LaverW. G.1963; An immunological study of avian, viral and bacterial neuraminidase based on specific inhibition of enzyme by antibody. J. gen. Microbiol 32:225
AminoffD.1961; Methods for the quantitative estimation of TV-acetylneuraminic acid and their application to hydrolysates of sialomucoids. Biochem. J 81:384
KilbourneE. D.,
LaverW. G.,
SchulmanJ. L.,
WebsterR. G.1968; Antiviral activity of antiserum specific for an influenza virus neuraminidase. 1. In vitro effects. (In preparation)
KilbourneE. D.,
LiefF. S.,
ShulmanJ. L.,
JahielR. I.,
LaverW. G.1967; Antigenic hybrids of influenza viruses and their implications. Perspectives Virol 6:87
LiefF. S.,
CohenD.1965; Equine influenzaStudies on the virus and of antibody patterns in convalescent, interepidemic and post vaccination sera. Am. J. Epidem 82:225
LiefF. S.,
HenleW.1959; Methods and procedures for use of complement fixation technique in type-and strain-specific diagnosis of influenza. Bull. Wld Hlth Org 20:411
WebsterR. G.,
LaverW. G.1967; Preparation and properties of antibody directed specifically against the neuraminidase of influenza virus. J. Immun 99:49
WebsterR. G.,
LaverW. G.,
KilbourneE. D.1968; Reactions of antihaemagglutinin and antineuraminidase antibodies with two A0–A2 recombinant influenza viruses containing different amounts of A 2 neuraminidase. Virology (In the Press)