Antibodies Activated by Hepatitis B Vaccines
The primary antibody activated by hepatitis B vaccination is anti-HBs (antibody to hepatitis B surface antigen), which provides protection against hepatitis B infection when levels reach ≥10 mIU/mL. 1
Serological Response to Hepatitis B Vaccination
The hepatitis B vaccine contains hepatitis B surface antigen (HBsAg) produced in yeast by recombinant DNA technology. When administered, it stimulates the immune system to produce:
- Anti-HBs antibodies: These antibodies specifically target the hepatitis B surface antigen and are the key protective element induced by vaccination
- HBs-specific T cells: These complement the antibody response and contribute to long-term immunity
The serological marker profile after successful vaccination is:
- HBsAg: Negative
- Total anti-HBc: Negative
- IgM anti-HBc: Negative
- Anti-HBs: Positive (≥10 mIU/mL)
This pattern distinguishes vaccine-induced immunity from immunity acquired through natural infection, which would show positive anti-HBc 2, 1.
Development of Protective Immunity
The development of protective immunity follows a predictable pattern after vaccination:
- After the first dose: 30-55% of adolescents aged <40 years achieve protective antibody levels
- After the second dose: Approximately 75% achieve protective levels
- After the third dose: >90% achieve protective levels 2
Recent clinical trials with newer vaccines like Heplisav-B have shown protective antibody responses in approximately 90% of participants, compared with 70.5%-90.2% of participants receiving older vaccines like Engerix-B 2.
Long-term Protection
Vaccine-induced immune memory has been demonstrated to persist for more than 30 years 2. Even when antibody levels decline below detectable limits, immunologic memory often persists, providing ongoing protection 1.
This memory is evident from:
- Rapid increases in antibody levels following booster vaccination, even in subjects who have lost detectable antibody
- Persistence of memory B lymphocytes capable of producing anti-HBs 3
Important Distinctions in Antibody Response
It's important to note that hepatitis B vaccination:
- Induces anti-HBs antibodies but not anti-HBc antibodies
- Does not provide sterilizing immunity (complete prevention of viral entry)
- Creates primarily CD45RO-CCR7-CD127- terminally differentiated cells specific to HBsAg 4
This differs from natural infection, which generates both anti-HBs and anti-HBc antibodies, along with T-cell responses to multiple viral antigens including HBcore and polymerase proteins 4.
Clinical Significance
The presence of anti-HBs at levels ≥10 mIU/mL is considered protective against hepatitis B infection 1, 5. This level is the standard threshold used to determine successful immunization and protection against future infection.
Higher levels (>100 mIU/mL) may provide more robust protection, especially in immunocompromised individuals 1.
Understanding the specific antibody response to hepatitis B vaccination is crucial for interpreting serological test results and determining immune status in vaccinated individuals.