Vaccination of newborns of HBsAg-positive carrier mothers with a recombinant DNA hepatitis B vaccine.

Thirty neonates born to HBsAg-positive mothers were vaccinated with a 20 microgram dose of the SmithKline Biologicals recombinant DNA yeast-derived vaccine within 24 hours after birth, with similar inoculations repeated 1 and 2 months later. Preliminary results indicate that the recombinant vaccine was well tolerated and immunogenic. A 100% seroconversion rate was achieved 4 months after the first vaccine dose and the anti-HBs geometric mean titres progressively rose from 14 to 31,279 and 361 IU/l at months 1, 2, 4, and 6, respectively. Although a longer period of observation and comparison with a historical control group are needed to evaluate its protective efficacy in this high-risk population, the fact that no vaccinated newborns have been infected is encouraging.