Efficacy of hepatitis B vaccine in prevention of early HBsAg carrier state in children. Controlled trial in an endemic area (Senegal).

Three doses of inactivated hepatitis B vaccine were given at one-month intervals to Senegalese children aged less than two years. A control group received diphtheria/tetanus/polio vaccine. Of those HB vaccine recipients who were seronegative before immunisation, 94.5% had a specific anti-HBs response. Anti-HBs of maternal origin did not interfere with the active immunisation. HB vaccine was without ill-effects, irrespective of hepatitis B marker status before immunisation. After twelve months' follow-up, the incidence of the HBsAg carrier state was reduced by 85% in susceptible children (p less than 0.0001).