[A new influenza subunit vaccine: reactogenicity and antigenicity in comparison to split and whole virus vaccines (author's transl)].

The reactogenicity and immunogenicity of a new influenza subunit vaccine essentially containing only haemagglutinin and neuraminidase was studied in man. The vaccine was compared to commercially available vaccines, an adjuvant containing tween-ether split vaccine (800 IU per dose), and a fluid whole-virus vaccine (2100 IU per dose). Two dosages (700 and 2100 IU) of the fluid subunit vaccine were compared. All vaccines contained the virus strains recommended by the WHO for the 1975/76 season. In a double-blind study 399 volunteers were randomly selected to receive one of the four vaccines. The volunteers were examined for side-effects 24 and 48 hr after vaccination. Antibodies inhibiting haemagglutination were determined prior to and four weeks after vaccination. The sudunit vaccine at 700 IU per dose caused significantly fewer local side effects than the comparable split vaccine, and resulted in significantly higher antibody titers against both influenza A strains. A comparison of the subunit and whole virus vaccines containing high dosages (2100 IU) showed striking differences in reactogenicity. Subunit vaccine was very well tolerated. whereas whole virus vaccine caused systemic reactions, including fever and headache, in 15% of the volunteers. No significant reactogenicity was seen with a high dosage of subunit vaccine (2100 IU) although this is a three-fold increase on the currently used European dosage. Antibody titers were significantly enhanced however.