Should a healthcare professional who performs invasive procedures and who once had a positive anti-HBs result be revaccinated if the anti-HBs titer is rechecked and is less than 10 mIU/mL?
No. Immunocompetent people known to have responded to HepB vaccination in the past do not require additional passive or active immunization. Postvaccination testing should be done 1–2 months after the original vaccine series is completed. In this scenario, the initial postvaccination testing showed that the healthcare professional was protected. Substantial evidence suggests that adults who respond to a HepB series (anti-HBs of at least 10 mIU/mL) are protected from chronic HBV infection for at least 30 years, even if there is no detectable anti-HBs currently. Only immunocompromised people (for example, dialysis patients, some people living with HIV) need to have anti-HBs testing performed periodically. Booster doses of vaccine to maintain their protective anti-HBs concentrations to at least 10 mIU/mL are recommended for dialysis patients and may be given to some people living with HIV.
CDC