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Challenge with hepatitis B vaccine in children previously vaccinated with a hepatitis B-containing combination
Philippe Reinert1, Sandro Cinquetti, Benoit Soubeyrand
1Centre Hospitalier Intercommunal de Créteil, France.
Insights
Infant hepatitis B virus (HBV) vaccination provides lasting protection through immune memory, even if antibody levels decrease. A booster dose is generally not needed, confirming long-term efficacy.
Area of Science:
- Immunology
- Vaccinology
- Public Health
Background:
- Hepatitis B virus (HBV) vaccination is recommended globally for infants.
- Antibody levels decrease post-vaccination, but immune memory is believed to persist.
- Over 160 countries have integrated HBV vaccination into infant programs.
Purpose of the Study:
- To assess the persistence of protection after infant hepatitis B virus (HBV) vaccination.
- To evaluate the immune response to a challenge dose of HBV vaccine in children with low antibody levels.
Main Methods:
- Children vaccinated with Hexavac or Primavax in infancy received an HBV vaccine challenge dose.
- Participants had anti-HBs concentrations below the seroprotective threshold before the challenge.
- Immune response was measured by anti-HBs concentrations one month post-challenge.
Main Results:
- A high percentage of children responded to the HBV vaccine challenge (88.5% for Hexavac, 85.0% for Primavax).
- These percentages represent a boosted response in children with previously low antibody levels.
- The study excluded children who still had protective antibody levels, suggesting even higher overall protection.
Conclusions:
- Infant HBV vaccination induces durable immune memory.
- This immune memory allows for a robust response to a booster vaccine, even after antibody levels decline.
- A full primary vaccination schedule in infancy likely confers long-term protection without the need for additional HBV doses.
Introduction:
The World Health Organization (WHO) recommends universal infant hepatitis B virus (HBV) vaccination as the most effective preventive measure against HBV-induced disease in endemic areas. More than 160 countries have followed the WHO recommendations to incorporate HBV vaccination in their national infant immunization programs. While antibodies to hepatitis B surface antigen (anti-HBs) concentrations progressively decrease following vaccination in infancy, protection persists, probably due to lasting immune memory. Hence, it is thought that future exposure to wild-type virus or HBV vaccine will induce a protective secondary immune response.
Methods:
Children aged 7-8 years old who had been vaccinated in infancy with a hexavalent DTacP-IPV-HB-Hib vaccine (Hexavac(R); Sanofi Pasteur MSD, Lyon, France) and children aged 7-9 years vaccinated in infancy with a DT-HB vaccine (Primavax(R); Sanofi Pasteur MSD), whose anti-HBs concentrations had fallen below the seroprotective threshold of 10 mIU/mL at age 4.5-6 years, received a challenge dose of monovalent HBV vaccine (HBVAXPRO(R); Sanofi Pasteur MSD) to assess persistence of protection.
Results:
One month postchallenge, 54 of 61 (88.5%) Hexavac-primed seronegative children and 34 of 40 (85.0%) Primavax-primed seronegative children had anti-HBs concentrations > or =10 mIU/mL. The percentage of protected children would have been even higher if the children who still had protective antibody levels (who were not included in this challenge study) had been assessed (42.1% with Hexavac, 55.4% with Primavax).
Conclusion:
Vaccination with a HBV-containing multivalent vaccine during infancy induces a lasting immune memory that can be boosted, even in children with a decline in anti-HBs concentrations. The present results confirm that the full primary vaccination schedule in infancy seems to confer long-term protection via immune memory and that an additional HBV dose is not generally required.
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