Hepatitis B vaccination with short dose intervals--a possible alternative for post-exposure prophylaxis?

To achieve a more rapid antibody response following hepatitis B (HB) vaccination, vaccine injections were given to medical students at considerably shorter intervals than usually recommended. They received 10 micrograms of the Merck Sharp & Dohme recombinant HB vaccine at time 0, 2 and 6 weeks (27 vaccinees) or were vaccinated according to the recommended schedule for pre-exposure HB prophylaxis (0, 1 and 6 months) (26 vaccinees). The short interval regimen resulted in a significantly higher frequency of protective antibody levels (greater than or equal to 10 IU/l) two weeks after the second dose of vaccine (48% vs. 4%; p less than 0.001), and all short interval vaccinees had seroconverted within two months (i. e. two weeks after the third dose). The recommended interval regimen resulted in a slower development of antibodies but significantly higher peak antibody levels after the completed three doses (p less than 0.001). The results indicate that protective antibody levels against hepatitis B virus (HBV) can be achieved more rapidly in humans through vaccination with short intervals. This short interval vaccination regimen, which has proved effective for post-exposure prophylaxis in chimpanzees, should possibly also be considered for post-exposure prophylaxis in humans, for instance after accidental exposure to HBV-contaminated blood.