[Human and animal Hong Kong series influenza viruses]

Investigation of influenza viruses isolated from man and animals and having hemagglutinin of the H3 subtype according to the new nomenclature (H3, Heq2 and Hav7 according to the old nomenclature) by serological methods (including the use of monoclonal antibody) and oligopeptide mapping showed that many animal isolates reflected an antigenic drift of the Hong Kong virus series which has been going on since 1968 until now. At the same time a number of isolates represent precursors of viruses of the Hong Kong series circulating among the human population. It is suggested that this is not the first time that viruses of the Hong Kong series have been introduced into the human population.