[Studies of the distribution of hemagglutination inhibiting antibodies against A/Victoria/3/75 (H3N2), B/Hong Kong/8/73 and A/New Jersey/76 (Hsw1N1) influenza viruses in a Turin population sample].

53%, and 29.8% respectively, of a sample of 500 adults living in Turin have been shown lacking of any antibody against A/Victoria/3/75 and B/Hong Kong/8/73 influenza strains; less than 20%, and 45.4% respectively, possessed antibodies at a protective level (greater than or equal to 1:40). Furthermore, the study of age distribution of immunity against A/New Jersey/76 has confirmed specific h.a.i. antibodies to be present, at a significant level, only from the sixth decade onwards.