Question
Vaccination against hepatitis B
Answer
Hepatitis B vaccine is a recombinant, subunit vaccine containing purified Hepatitis B surface antigen (HBsAg), produced by recombinant DNA technology (expressed in yeast) — highly effective at preventing HBV infection and its long-term complications.
Schedule: a birth dose (within 24 hours of birth, particularly important for preventing perinatal transmission from HBsAg-positive mothers) followed by additional doses as part of the primary series (e.g., at 6, 10, and 14 weeks, often combined in the pentavalent vaccine).
Mechanism: stimulates active production of anti-HBs antibody; being a subunit (non-live) vaccine, it carries no risk of causing HBV infection and is safe even in immunocompromised individuals.
High-risk group vaccination: recommended for healthcare workers, dialysis patients, household contacts of HBsAg-positive individuals.
Post-exposure prophylaxis: Hepatitis B Immunoglobulin (HBIG) plus vaccination is given to neonates born to HBsAg-positive mothers, and to individuals with high-risk needle-stick/mucosal exposure, combining immediate passive protection with the vaccine’s active, longer-term immunity.
Efficacy monitoring: anti-HBs antibody titre can be checked post-vaccination in high-risk groups to confirm adequate seroconversion (a titre ≥10 mIU/mL is generally considered protective).
Public health significance: universal infant HBV vaccination has dramatically reduced the incidence of chronic HBV infection, hepatocellular carcinoma, and cirrhosis in vaccinated cohorts, and is a cornerstone of national immunization programmes worldwide.