Infants vaccinated against HBV may have lost surface antigen protection during adolescence
Recipients of hepatitis B vaccination at infancy may lose their hepatitis B surface antigen immunological memories by adolescence, according to recent results.
Researchers tested 8,733 Taiwanese high school students born between July 1987 and July 1991 for hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs). Most participants (n=7,914) had documented hepatitis B immunizations before age 3 years, including 381 who received hepatitis B immunoglobulin (HBIG).
HBsAg positivity was detected in 1.9% of the evaluable cohort, and anti-HBs was observed in 48.3%. Investigators noted an association between dosage and HBsAg positivity (P=.0085 for trend). Those who received either one to two or three doses of vaccine were more likely to test positive for HBsAg than those who received four doses (OR=2.38; 95% CI, 1.74-4.84 for one to two doses; OR=1.40; 95% CI, 0.92-2.14 for three doses).
Similar trends were observed among the 7,537 patients who did not receive HBIG (OR=2.85; 95% CI, 1.39-5.81 for one to two doses; OR=1.52; 95% CI, 0.91-2.53 for three doses), but not among the patients who did. HBIG recipients were more likely to be HBsAg-positive than those who did not receive HBIG (15.4% vs. 1.3%, adjusted OR=15.63; 95% CI, 10.99-22.22).
Patients whose mothers were HBeAg-positive (n=162) had higher rates of HBsAg positivity than those with negative maternal HBeAg status (17.8% vs. 11.1%; P=.014). Within this subgroup, fewer participants vaccinated on their birth date were HBsAg-positive than those vaccinated the next day (14.9% vs. 29.0%, P=.032).
Researchers administered a booster vaccination to 1,974 HBsAg- and anti-HBs-negative participants, including 1,252 recipients with pre-booster anti-HBs titers less than 1.0 mIU/mL and 722 with titers between 1 mIU/mL and 9.9 mIU/mL. Anti-HBs seropositivity increased from 48.3% to an estimated 84.3% after the booster.
“A significant proportion of adolescents who had received primary infantile HB vaccination may have lost their immunological memories against HBsAg,” the researchers wrote. “Routine use of anti-HBV treatment during pregnancy might be an option, if safety and efficacy are proven by further large-scale studies. Booster HB vaccination in subjects aged 15 years or more should be considered, especially in subjects born to HBsAg-positive mothers or who have a high risk of HBV exposure.”