[Antibody response to hemagglutinin and neuraminidase induced by an influenza subunit vaccine (author's transl)]

To study antigenicity, persistence of antibody (efficacy) and reactogenicity of a new bivalent influenza subunit vaccine, Sandovac, it was given in two different concentrations (1000 and 2000 IU) to 156 subjects from two epidemiologically destinct areas (119 students from Essen, average age 22 years, 37 residents from Kassel average age 56 years). Serum antibody response was measured by hemagglutination inhibition (HI) and neuraminidase inhibition (NI) tests before, one, two and six months after vaccination. The following results were obtained: 1. Four weeks post vaccination an excellent strain specific and crossreactive (H3 N2 variant-specific) antibody response was observed. Subtype specific (H0, H1 or H2) activity could not be detected. 2. Six months post vaccination a still notably higher antibody level as compared to the preimmunization status could be demonstrated. 3. A difference, however, existed between the immune responses of the Essen student population with an average age of 22 years, and of the Kassel resident population with an average age of 56 years. The immune response being significantly better in younger vaccinees. 4. High and low concentrated vaccines revealed neither objective nor subjective differences in reactogenicity and were very well tolerated. 5. In all immunological parameters tested the double concentrated vaccine (S 2000) proved to be slightly superior to the lower concentrated vaccine (S 1000) that is officially licensed in the German Federal Republic.