Effectiveness of universal hepatitis A immunization of children in Minsk City, Belarus: four-year follow-up.
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.
Fisenka
E G
EG
Municipal Center of Hygiene and Epidemiology, Minsk, Belarus. fisenko.l@rambler.ru
Germanovich
F A
FA
Glinskaya
I N
IN
Lyabis
O I
OI
Rasuli
A M
AM
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005500:Follow-Up Studies; D006506:Hepatitis A / Q000453:epidemiology* / Q000517:prevention & control*; D035922:Hepatitis A Antibodies / Q000097:blood; D022362:Hepatitis A Vaccines / Q000008:administration & dosage*; D006801:Humans; D017589:Immunization Programs / Q000592:standards*; D007223:Infant; D011159:Population Surveillance; D002094:Republic of Belarus / Q000453:epidemiology; D016036:Seroepidemiologic Studies; D014611:Vaccination / Q000706:statistics & numerical data*; D055815:Young Adult
D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines