PERSISTENCE OF ANTI-HBS IN CHILDREN VACCINATED AGAINST VIRAL-HEPATITIS-B IN THE FIRST-YEAR OF LIFE - FOLLOW-UP AT 5 AND 10 YEARS

The persistence of anti-HBs protective levels in groups of children wh o had been immunized against Hepatitis B 5 and 10 years earlier, in th eir first year of life, has been studied. The results were analyzed ac cording to the type of vaccine (both plasma-derived and DNA recombinan t) and the number of doses administered (three or four doses). In addi tion, the protective effect of the vaccine in vaccinated subjects was studied in relation to the anti-HBc presence. The serologic results su ggest that, in cohorts of children vaccinated 5 years earlier, a highe r prevalence of subjects with anti-HBs protective levels was found, wh en the DNA recombinant vaccines were administered (97.6% for MSD Recom bivax and 97.1% for SKF Engerix B); a lower one when the plasma-derive d vaccine was used (80.4% Pasteur Merieux, Hevac B). Moreover, in coho rts of children vaccinated with plasma derived vaccine (Hevac B) 10 ye ars earlier, a higher prevalence of subjects with anti-HBs protective levels was demonstrated when four doses were administered (76.9%), a l ower one when three doses were inoculated (57.5%). The absence of core antibody (anti-HBc) in responders to the vaccination shows the protec tive efficacy of both the DNA recombinant and plasma derived vaccines. On the other hand the presence of anti-HBc in some anti-HBs negative non-responders subjects shows the susceptibility of these people to in fection. In anti-HBs negative vaccinated subjects the appearance of le vels of anti-HBs in 95.9% of subjects, I week after the administration of a booster dose, demonstrates the presence of a solid immunologic m emory. Copyright (C) 1996 Elsevier Science Ltd.