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Immune memory and immune response in children from Bulgaria 5-15 years after primary hepatitis B vaccination

Pavel Teoharov1, Ani Kevorkyan, Nedyalka Petrova

  • 1Department of Virology, National Centre of Infectious and Parasitic Diseases, Sofia, Bulgaria. teoharov.pavel@gmail.com

The Pediatric Infectious Disease Journal
|August 24, 2012
PubMed

Insights

Hepatitis B vaccination in children provides lasting protection up to 15 years. Most children maintained protective antibodies, and all showed a strong immune memory response after a booster dose, indicating sustained immunity.

Area of Science:

  • Immunology
  • Vaccinology
  • Pediatrics

Background:

  • Bulgaria implemented universal infant hepatitis B vaccination in 1991.
  • Limited studies have assessed long-term hepatitis B vaccine protection in children.
  • This study aimed to evaluate the duration of protection in children post-vaccination.

Purpose of the Study:

  • To investigate the duration of protection against hepatitis B in children aged 5-15 years after primary immunization.
  • To measure the immune and anamnestic immune response.
  • To identify any breakthrough hepatitis B infections.

Main Methods:

  • 141 children (5-17 years) were grouped by time since primary immunization (approx. 5, 10, 15 years).
  • Hepatitis B markers (HBsAg, anti-HBc, anti-HBs) were measured.
  • A booster dose was given to children with anti-HBs <10 mIU/mL, with antibody levels assessed before and after.

Main Results:

  • 67.4% of children had protective anti-HBs antibodies.
  • Seroprotection rates were 84.6% (5 yrs), 55.8% (10 yrs), and 61.1% (15 yrs).
  • 100% of children showed an anamnestic immune response after a booster dose, with GMC of 337.38 mIU/mL.

Conclusions:

  • Recombinant hepatitis B vaccines induce long-term immune memory and protection in children.
  • Immune memory persists for at least 15 years after primary infant immunization.
  • The findings support the continued efficacy of infant hepatitis B vaccination programs.
Abstract

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