Q: Do patients who received only two doses of hepatitis B vaccine need a booster?

The Advisory Committee on Immunization Practices (ACIP) currently recommends that people who have not completed the three-dose vaccination series against hepatitis B virus (HBV) should receive the missed doses: ie, the three-dose regimen does not need to be restarted.1 However, evidence suggests that a two-dose regimen may provide adequate seroprotection for healthy young adults. As the three-dose regimen has been shown to protect 90% to 100% of adults,2 it has gained widespread acceptance and is now standard clinical practice.2 However, deviating from the three-dose regimen may not leave healthy young adults vulnerable to HBV infection.