STUDIES ON HEMAGGLUTINATING ACTIVITY, INFECTIVITY AND IMMUNIZING ABILITY OF INFLUENZA VIRUS

We studied the hemagglutinating activity, infectivity and immunizing ability of influenza virus FM1 (egg-adapted strain and mouse-adapted strain). The mouse-adapted strain FM1 had infectivity, immunizing ability and toxicity against chick embryo proportion to its hemagglutinating activity, but not against mice.After we repeated the adsorption of virus in virus-suspension with chick red cells, we inoculated the 10-1-10-5 dilution of that non-hemagglutinating supernatant into the chorioallantoic cavity of eggs, and, after 48 hours' incubation, we recognized the virus-production by their hemagglutination. So that there may be the non-hemagglutinating but infective influenza virus.