[Hepatitis B vaccine inhibiting vertical transmission of hepatitis B virus].

A survey of hepatitis B virus infection was carried out among 1,947 pregnant women. The results showed that 215 women were HBsAg positive, a rate of 10.7%. Among the 38 serum samples reexamined, 10 were positive both for HBsAg and HBeAg (26.3%). In order to evaluate the effect of hepatitis B vaccine on inhibiting vertical transmission, all infants of the 38 women positive for HBsAg were given hepatitis B vaccine 40 micrograms. by injection 7 months after the immunization, HBsAg was found absent in 31 of them, but all the infants had produced anti-HBsAg antibody. The positive rate of anti-HBsAg antibody in infants whose mothers had both positive HBsAg and HBeAg was 50%, whereas in infants whose mothers had only positive HBsAg it was 92.9% (chi 2 = 6.38 P less than 0.05).