[Variability of hemagglutinin and nucleoprotein proteins in the "Spanish" series of influenza viruses].

Oligopeptide mapping and immunological methods were used to study influenza viruses of the evolutionary series Hsw1-H0-H1 isolated from man and animals. Among the animal viruses some possess hemagglutinins similar to those observed in the viruses isolated from man, while some viruses differ from them. These are assumed to be precursors of the viruses of "Spanish" influenza retained in animals. Variability of the nucleoprotein protein in the viruses under study was observed.