Hepatitis B vaccine immunoresponsiveness in adolescents: a revaccination proposal after primary vaccination.

Hepatitis B recombinant vaccine immunoresponsiveness was studied in 427 preadolescents vaccinated with a 0, 1 and 6 months vaccination schedule. AntiHBs postvaccination titres (measured one month after the last dose) were related to the following variables: sex; weight; height; and Quetelet index. The antiHBs postvaccination titres were used to predict the length of protection induced by the vaccine. All preadolescents developed antiHBs titres 10 IU l-1 and no statistically significant differences could be found between sexes. The relation study between antiHBs postvaccination levels and Quetelet index showed a statistically significant inverse correlation. According to the antiHBs postvaccination titres, the central 50% of the sample distribution would be protected during a period between 7.5 and 10.5 years. In pre-teenagers, the hepatitis B recombinant vaccine has proven to be highly immunogenic, obesity is a predictor of poor immunoresponse and this response is not influenced by sex. According to our results, we would propose the administration of a single booster dose 10 years after primary vaccination and thus protect these subjects during the period of greatest risk.