Active immunization against hepatitis B: immunogenicity study in homosexual men.

In a group of 238 homosexual men a hepatitis B vaccine developed at the National Reference Center for Viral Hepatitis (Göttingen/Germany) was evaluated. The vaccine was well tolerated. Three intramuscular injections of inactivated HBsAg (subtype ad; 11300 Natl. Units/dose) induced antibody production in 89.7% of the subjects. Four participants exhibited signs of hepatitis B infection. Vaccine recipients younger than 30 years produced higher antibody levels than older vaccinees. More than one half of the subjects who had only anti-HBs (anti-HBc negative) prior to immunization did not show an anamnestic booster response but formed IgM-anti-HBs. Antibody levels were significantly lower in anti-HBs negative/anti-HBc positive recipients than in subjects who had only anti-HBs or no hepatitis B markers. Immunological studies of T and B cell function did not provide conclusive evidence for the underlying cause of the different immune responses.