THE EFFECT OF ULTRAVIOLET IRRADIATION ON VARIOUS PROPERTIES OF INFLUENZA VIRUSES

The effect of ultraviolet irradiation on various properties of the influenza viruses Types A and B has been analyzed. The studies involved propagation and interference in the allantoic sac of the chick embryo, inhibition of embryonic development, toxicity for white mice, hemagglutination including the adsorption-elution mechanism, immunizing capacity for mice and, finally, complement fixation activities in the presence of antibodies to the 600S antigen (human convalescent and postvaccination sera) and the 30S antigen (convalescent sera only). It has been shown that the various activities of the influenza viruses were affected by irradiation at different rates, indicating that they are based, at least in part, on different constituents of the virus particle. On account of these differences in the susceptibility of the various properties to ultraviolet light it was possible (a) to differentiate between the interference phenomenon as observed in the allantoic sac, and the development of non-agglutinability in red cells by either homologous or heterologous fresh virus, and (b) to separate individual steps involved in the mechanism of infection of susceptible host cells. The implications of these findings are discussed.