Effectiveness of universal hepatitis A immunization of children in Minsk City, Belarus: four-year follow-up

J Viral Hepat. 2008 Oct:15 Suppl 2:57-61. doi: 10.1111/j.1365-2893.2008.01031.x.

Abstract

Hepatitis A is a reportable disease in Belarus. Universal hepatitis A vaccination of children aged 6 years in Minsk City began in 2003. This analysis was conducted to evaluate the short-term impact of the program. Hepatitis A incidence data from 1954 to 2006 was compiled. Vaccination effectiveness was estimated by comparing the incidence of reported hepatitis A cases after 4 years of immunization (2006) with the incidence when the vaccination program started (2003). The vaccines used were Avaxim 160 or Avaxim 80 (95%) and Havrix 720 (5%). From 2003 through 2006, hepatitis A incidence in vaccinated children under 14 years was 20-fold lower than the incidence in unvaccinated children (0.3 cases/10000 vs 5.98/10000; odds ratio = 0.05, 95% CI: 0.012-0.202), for a vaccination effectiveness of 95%. The decreased incidence of hepatitis A in all age groups in 2006 (by 12 times in preschool children aged 1-5 years, 13 times in children aged 10-14 years and 4-6 times among adults), including those without high coverage by vaccination, suggest a herd effect. Routine vaccination also resulted in a shift of the age pattern of hepatitis A morbidity. The proportion of cases in children under 14 years decreased from 33% to 41% in 2000-2002 to 7% in 2005-2006. We conclude that introduction of universal hepatitis A vaccination in Minsk resulted in sharply reduced incidence in both vaccinated and unvaccinated children. Hepatitis A virus circulation might decrease further by beginning vaccination at a younger age.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Disease Outbreaks
  • Follow-Up Studies
  • Hepatitis A / epidemiology*
  • Hepatitis A / prevention & control*
  • Hepatitis A Antibodies / blood
  • Hepatitis A Vaccines / administration & dosage*
  • Humans
  • Immunization Programs / standards*
  • Infant
  • Population Surveillance
  • Republic of Belarus / epidemiology
  • Seroepidemiologic Studies
  • Vaccination / statistics & numerical data*
  • Young Adult

Substances

  • Hepatitis A Antibodies
  • Hepatitis A Vaccines