20-µg hep B vaccine can prevent vertical transmission

Using a 20-µg dose to vaccinate children born to mothers with detectable levels of hepatitis B virus surface antigen (HBsAg) appears to avert vertical transmission, reports a recent China study.

The study included 419 HBsAg-positive pregnant women who were asked to accomplish a questionnaire for basic medical and sociodemographic information. Blood samples were also drawn for the assessment of hepatitis B virus (HBV) infection. A total of 430 infants were included in the analysis, all of whom had been given three 20-µg doses of the HBV vaccine.

One month after the final vaccine dose, analysis of blood samples from the infants showed that only six (1.9 percent) tested positive for HBsAg; the rest were negative to the biomarker. Of the remaining 313 evaluable and HBsAg-negative infants, 95.8 percent (n=300) showed detectable levels of antibodies against the hepatitis B surface protein, with a geometric mean concentration of 861.8 mIU/mL.

In particular, more than 80 percent of these infants (n=260) had antibody levels above 100 mIU/mL.

All six HBsAg-positive infants were born to mothers who were strongly positive for the hepatitis B e antigen (HBeAg). Five were born to mothers with HBV DNA levels exceeding 5 ×10⁸ IU/mL.

“It is crucial to enhance health education for childbearing age women so that they may participate in early HBsAg screening and be aware of their HBV infection status,” the researchers said. “Although several technical guidelines have recommended antiviral therapy for HBsAg-HBeAg positive pregnant women or those with a higher HBV DNA level, a more viable treatment procedure for greater prevention of HBV MTCT is still lacking in China, even worldwide.”