[Respective importance of vertical and horizontal transmission of hepatitis B in the Australian archipelago (French Polynesia). Preliminary results of the vaccination of newborns].

A seroepidemiological survey of hepatitis B was conducted in 1988 in the Austral archipelago (French Polynesia) in a randomly selected sample of 957 persons, has showed an infection rate (at least one positive marker) with HBV of 64.1% for the entire archipelago. Among women of child-bearing age, HBs Ag carriage rate was 11.45% of whom 19.1% were so HBe Ag carriers. Among infants HBs Ag carriage rate was 2.1% and among juveniles it was 10.6%. In this area horizontal transmission of HBV is essential. An immunization program was implemented in August 1988 using a recombinant vaccine (GenHevac BTM). At one year of the program, 97% of the children had received at least one dose of vaccine, 90% had HBs-antibodies titer higher than 10 mUI/ml, 96% had seroconverted for at least one of the two antibodies (anti-HBs and/or anti-preS2) and any of them was neither HBs Ag carrier nor anti-HBc IgM antibodies carrier. Finally, among 7 neonates whose mother were positive for both HBs Ag and HBe Ag, 6 were immunes and the last one, aged of 1 month (one dose received only), was not HBs Ag carrier. These preliminary results show that vaccination with GenHevac BTM to be immunogenic and effective in field conditions.