Primary vaccination against hepatitis B virus (HBV) at birth may not provide adequate lifelong antibody levels, but a booster vaccine at age 18 years reinforces antibody levels for at least 4 more years, according to a study published in Infectious Diseases.

Vaccination against HBV is recommended in the first year of life to prevent infection, and studies demonstrate that this provides protection for 90% of the population for 30 years. Data on response to booster doses and long-term protection are lacking; therefore, researchers sought to understand the protection duration of the HBV vaccine and the effect of additional doses on the level of protection against infection.

The researchers conducted a retrospective analysis of data from January 2013 to December 2016 of healthcare students in Israel. Participants were aged 19 to 25 years. Immunization history was obtained from medical records, including data for receipt of birth-dose HBV vaccine and booster at age 18 years. This booster is common in Israel, as many teenagers undergo emergency medical technician training that requires HBV vaccination regardless of previous immunization. Baseline antibody titer levels were measured at first clinic visit. A participant was considered protected against HBV if their anti-HBs titer was >10 MIU/mL; any participant with titers below this level received a booster dose of the HBV vaccine.

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The researchers compared HBV antibody levels of 381 healthcare students who were immunized for HBV with a primary series during their first year of life (primary group, 80.1%) with those of participants who were immunized with a primary series and who received an additional dose at age 18 years (boosted group, 19.9%) 4 years earlier. They found that 88.1% of participants in the boosted group had antibody levels ≥10 mIU/mL compared with 41.3% of those in the primary group (P <.001). Among the participants in the primary group, 179 had inadequate antibody levels, of whom 134 received a booster dose; 126 of these participants (93.4%) developed antibody levels ≥10 mIU/mL. Nine participants in the boosted group had inadequate antibody levels, so 8 received another booster dose, and all developed adequate antibody levels.

The study authors concluded that, “Primary vaccination against HBV at birth does not necessarily provide lifelong adequate antibody levels.” Although current guidelines recommend testing and boosting all medical personal, the authors added that, “based on our study, it may be prudent to extend this practice to all individuals who are at higher risk.”

Reference

Hess L, Riesenberg K, Rolston KVI, Nesher L. Administering an additional hepatitis B vaccination dose after 18 years maintains adequate long-term protection levels in healthcare workers [published online January 25, 2020]. Infect Dis. doi:10.1080/23744235.2020.1718201