A study was made of the formation of recombinations between human viruses of types A2, A and the duck influenza virus. Recombinations could be obtained only with the viruses possessing a common soluble antigen (virus A2 and duck influenza virus). Some of the signs of parenteral strains were lost by the recombinations already during the second passage, whereas some were retained for 18 passages. Recombinations were obtained with the influenza viruses either adapted or nonadapted to chick embryos.
Introduced by V. M. Zhdanov, Active Member of AMN SSSR Translated from Byullenten'' Éksperimental''noi Biologii i Meditsiny, Vol. 58, No. 8. pp. 94–97, August, 1964