Identification of the antigenic components of the host cell in isolated glycoproteins of the influenza virus

: Immunological analysis performed by solid-phase enzyme immunoassay and complement fixation test revealed the presence of host cell antigenic components in purified intact influenza virions and isolated hemagglutinins and glycoproteins. Three antigens inherent to chick embryo cells were identified in virus preparations: the species-specific antigen, heterogenetic Forssman antigen, and one similar to human group A antigen. Antisera to purified whole-virion influenza vaccines, to glycoproteins and to hemagglutinin isolated from them were found to contain antibody populations which were conducive to broad cross reactions between them and heterotypic virus antigens. To avoid erroneous results, these antibody populations must be removed from the sera by pre-adsorption with host cell antigens.