Hepatitis B vaccine boosters unneeded for patients with residual anti-HBs
Individuals with residual antibodies to the hepatitis B surface antigen after a challenge dose vaccination did not appear to require boosters, according to recent findings.
In two clinical trials with 15-year follow-up, researchers vaccinated school-age children with 10 g Engerix (GlaxoSmithKline; n = 1,129) and 2.5 g Recombivax (Merck; n = 1,126). Participants received three doses of the vaccines (0, 1-2, and 6 months) at ages 8 to 10 years.
Both vaccines showed similar rates of seroconversion (99.1% with Engerix vs. 99.7% with Recombivax) and seroprotection (98.9% with Engerix vs. 99.2% with Recombivax), and nearly all participants (99.1%-100%) demonstrated the presence of immune memory, which was defined as at least 10 mIU/mL and a fourfold increase in anti-HB titer 1 month after challenge dose.
The researchers evaluated the response of participants to the challenge dose based on whether residual hepatitis B surface antigen (anti-HB) of 0.5–9.9 mIU/mL were detectable. Of the 228 participants with residual anti-HB levels, 99.1% met the criteria for immune memory, while 94% of the 84 participants without residual anti-HBs were considered to have immune memory.
Of those with immune memory, anti-HB titers of 10 or more mIU/mL persisted in 91.3% at 1 year, 77.3% at 5 years, and 64.4% at 10 years after the challenge.
“Our results indicate that virtually all those vaccinated with residual anti-HBs titers (0.5–9.9 mIU/mL) have an immune memory to the HBV surface antigen,” the researchers wrote. “In conclusion, our results ... suggest that there is no need for boosters in vaccinated individuals with residual anti-HB antibodies.” – by Jen Byrne
Disclosure: Gilca reports receiving research grants from GlaxoSmithKline and the Quebec Ministry of Health and Social Services. The clinical trials were financially supported by GlaxoSmithKline and the Quebec Ministry of Health and Social Services. Please see the full study for a list of all other authors’ relevant financial disclosures.