Immunity against influenza virus types A and B in the Ruhr region

: Haemagglutination-inhibiting antibodies against influenza virus types A and B were determined in the sera of 733 healthy persons among the population of the Ruhr region. The receptivity rate for the total population to strains A/Philippines 2/82 (H3N2) and A/Brazil 1/78 (H1N1) was 60% and 80%, respectively. It was as high as greater than 95% with respect to type B (Hongkong). These findings support the call for more widespread anti-influenza vaccination during the winter half-year.