[Seroconversion following immunization with a plasma-derived vaccine against hepatitis B: study of a 3-injection protocol (0, 1, 6 months) in Brazzaville (Congo)].

The aim was to study the immunogenicity of a plasma-derived vaccine against Hepatitis B Virus administrated in 3 injections at month 0-1-6. Only subjects without HBs Ag and anti-HBc were vaccinated. The seroconversion rates were 79.21% at day 90, 77.50% at day 180 and 87.21% at day 210. At the same dates, the mean geometric titres of anti-HBs (mUI/ml) were respectively 115.01, 100.48 and 772.78. In all subjects, the vaccine was very well tolerated. This 3 injections protocol of vaccination instead of the classical 4 injections protocol significantly reduces the cost of vaccination and may enlarge its application.