[Immunogenicity and long-term effectiveness of the hepatitis B vaccine in newborns from HBsAg-positive mothers].

We have followed up until age 2 years 25 infants who had received the hepatitis B vaccine to prevent being infected from their mothers who were HBsAg carriers. All had developed antibodies. At 2 years of age, 24% of infants had antiHBsAg titers lower than 10 mU/ml. The geometric mean of antiHBsAg titer in those infants who had received plasma derived vaccine was 660 mU/ml and in those having received recombinant vaccine was 903 mU/ml. HBsAg was negative in all the studied samples. In two infants positive antiHBc were detected.