Hepatitis B Vaccine

Introduction to the HepB Vaccine

The Hepatitis B (HepB) vaccine contains hepatitis B surface antigen (HBsAg) and induces an antibody response (anti-HBs) in the recipient, not an antigen response, as recommended by the Centers for Disease Control and Prevention (CDC) 1, 2
The HepB vaccine works by introducing purified HBsAg protein into the body, which then stimulates the immune system to produce antibodies against this antigen (anti-HBs), creating immunological protection, according to the CDC 1, 2

Current HepB vaccines in the US are produced using recombinant DNA technology and contain purified HBsAg protein (10-40 μg/mL) adsorbed to aluminum hydroxide, as stated by the CDC 1, 2
The antigen is synthesized by genetically modified yeast (Saccharomyces cerevisiae), as reported by the CDC 1

The vaccine triggers production of anti-HBs antibodies, providing protection against both acute disease and chronic HBV infection, as noted by the CDC 2, 3
Protective immunity is defined as anti-HBs levels ≥10 mIU/mL, according to the CDC 2

The HepB vaccine is highly effective at inducing protective antibody levels in healthy infants (~95% develop protective antibody levels after completing the 3-dose series) and healthy adults <40 years (>90% develop protective antibody levels after the complete series), as reported by the CDC 2
After the third dose, >95% of recipients achieve protective levels, according to the CDC 2

Anti-HBs levels decline over time, particularly in the first year after vaccination, but immunological memory persists for at least 20-30 years in most immunocompetent individuals, as noted by the CDC 2, 3
By 18 years post-vaccination, only about 16% of those vaccinated before age 1 maintain antibody levels ≥10 mIU/mL, compared to 74% for those vaccinated at age ≥1 year, according to the CDC 2

The vaccine-induced anti-HBs antibodies neutralize HBV particles, preventing infection, as stated by the CDC 2
Anti-HBs levels are measured to determine vaccine response and immunity status, according to the CDC 2
Most immunocompetent individuals don't require booster doses due to persistent immune memory, even when antibody levels fall below 10 mIU/mL, as reported by the CDC 2, 3
Immunocompromised individuals (e.g., dialysis patients, HIV-infected persons) may have reduced antibody responses and might benefit from modified dosing regimens, as noted by the CDC 3