Studies on the origin of pandemic influenza. I. Antigenic analysis of A 2 influenza viruses isolated before and after the appearance of Hong Kong influenza using antisera to the isolated hemagglutinin subunits.

Studies on the origin of pandemic influenza. I. Antigenic analysis of A 2 influenza viruses isolated before and after the appearance of Hong Kong influenza using antisera to the isolated hemagglutinin subunits.