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Vaccination against hepatitis A in children aged 12 to 24 months [corrected]

K Abarca1, I Ibañez, J Flores

  • 1Centro de Investigación Médica, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile. katia@med.puc.cl

Archives of Medical Research
|October 2, 2001
PubMed

Insights

This study found that an inactivated hepatitis A vaccine is safe and effective for toddlers aged 12-24 months. The vaccine demonstrated good immunogenicity, providing a strong immune response in young children.

Area of Science:

  • Pediatric infectious diseases
  • Vaccinology

Background:

  • Current hepatitis A vaccines have age restrictions, with some licensed for children over 2 years and others over 1 year.
  • Routine hepatitis A vaccination is recommended for children in high-endemicity areas, but data for toddlers aged 1-2 years is limited.

Purpose of the Study:

  • To evaluate the safety and immunogenicity of an inactivated hepatitis A vaccine in children aged 12-24 months.
  • To assess the reactogenicity and immune response following a two-dose vaccination schedule.

Main Methods:

  • An open clinical study involving 120 seronegative children aged 12-24 months.
  • Administered two doses of an inactivated hepatitis A vaccine (Havrix pediatric) on a 0, 6-month schedule.
  • Monitored for local and general symptoms and measured antibody levels.

Main Results:

  • The most common side effects were injection site pain and irritability.
  • No serious adverse events were associated with the vaccine.
  • High antibody levels against hepatitis A were observed: 159 mIU/mL after the first dose and 2,939 mIU/mL after the booster dose.

Conclusions:

  • The inactivated hepatitis A vaccine is well-tolerated in toddlers aged 12-24 months.
  • The vaccine effectively elicits a robust immune response in this age group.
  • Supports the potential use of this vaccine in younger children in high-risk areas.
Abstract

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