Improved methods of influenza virus propagation. II. Characteristics of cell culture and allantoic virus preparations.

Regular reproduction of influenza A virus with infectious titres of 7.4--8.5 log EID50/0.2 ml was observed in roller bovine embryo kidney cell cultures. The haemagglutinating activity of the cell culture preparations was 8-33-fold lower than that of the allantoic preparations, the infectivity being similar. Cell culture preparations of influenza A/Victoria/35/72 and A /Leningrad/538/74 viruses were markedly immunogenic in laboratory animals and antigenically active in complement fixation (CF) test. The CF activity of liquid and lyophilized preparations remained unchanged for 12--13 months (the period of observation). The stability of infectivity of lyophilized cell culture virus preparations was similar to that of allantoic virus preparations.