- D Desgrandchamps: Schweizerische Kommission für Impffragen, Baar.
Three comparable vaccines against hepatitis B, consisting of recombinant HBsAg, are registered in Switzerland. After intramuscular administration (deltoid, thigh), they induce seroconversion in 95% of subjects following a 0, 1, 6 or 0, 1, 2 and 12 months schedule. The determination of antibody titers is thus not required in healthy subjects in absence of an increased risk of exposure (healthcare workers). Vaccine induced protection is extended beyond the disappearance of specific antibodies, through the persistence of immunological memory, which reactivates immune defense mechanisms upon viral exposure. A booster immunization is thus not necessary after a full immunization course, even if given in the first year of life or in newborns of HBsAg positive mothers. The excellent safety profile of these vaccines (local pain 3-29%, fever 1-6%) allows their universal administration. Two combined vaccines are already available, and new vaccines may yet facilitate prevention of hepatitis B in the future by allowing a reduction in the number of doses required for protection.