The hepatitis B (HB) vaccine is effective for the prevention of HB virus infection. It has been widely accepted that an anti-HB surface antibody (HBs) level ≥10 mIU/mL is protective against HB virus infection. Although transient infection can occur in individuals who attain a peak level of anti-HBs ≥10 mIU/mL after primary vaccination, long-term follow-up studies show that successful primary vaccination can prevent individuals from acute clinical hepatitis and chronic infection. Healthcare workers (HCWs) are at-risk individuals. Based on the accumulated data, the USA considers an anti-HBs level ≥10 mIU/mL to constitute successful vaccination for HCWs. In contrast, because some anti-HBs assays cannot accurately measure in the low anti-HBs range, including 10 mIU/mL, the UK and Germany consider an anti-HBs level ≥100 mIU/mL to constitute successful vaccination for HCWs. In the USA and UK, a booster dose is unnecessary for HCWs after successful vaccination. In Germany, anti-HBs testing is recommended for HCWs who are at particularly high individual exposure risk 10 years after successful primary immunization, and a booster dose is offered if the anti-HBs level has declined to ˂100 mIU/mL. The differences in the goal of HB vaccination, reliability of anti-HBs assays, and use of booster vaccination cause discordance in HB vaccination policies for HCWs.
Keywords: booster; healthcare worker; hepatitis B virus; hepatitis B virus DNA; occult infection; prophylaxis; vaccine.
© 2019 The Japan Society of Hepatology.