Hepatitis B vaccination status in an at-risk adult population: long-term immunity but insufficient coverage

In France, hepatitis B (HB) vaccine has been offered to all infants since 1994, and was proposed to all children aged 11 years from 1994 to 1998. Nevertheless, HB vaccine hesitancy may result in low vaccination coverage in present-day at-risk adults. We aimed to determine HB vaccination coverage in adults attending a free testing center for sexually transmitted infections (STI). As part of routine care, three classes of data were anonymously collected from attendees over a 3-month period: results of HB serologic tests; date and number of past anti-hepatitis B virus (HBV) immunization(s) (if any) according to health records; and the risk of STI and blood-transmitted infections (BTI). The study included 735 participants (age 27.9 ± 9.2; 59.9% men). According to available health records (341 participants), 56.6% had received at least three and 67.2% at least one vaccine injection(s); 57.7% had received their last injection between 1994 and 1998, reflecting the strong vaccine policy during these years. Serologic testing (in 705 participants) showed evidence of a past or active HBV infection for 33 participants; of the remaining patients, 55.3% had anti-HBs antibody titers ≥10 IU/L. This rate was not higher in participants considered at risk for STI/BTI. Of the participants who received their last vaccine injection more than 15 years previously, 90.5% had anti-HBs antibody concentrations ≥10 and 60.3% ≥100 IU/mL. HB vaccination coverage is low in this population. Most of the vaccinated participants were immunized between 1994 and 1998, suggesting a failure of catch-up immunization of adolescents and at-risk adults. Long-term seroprotection persisted among vaccinated participants.