INTEGRATION OF HEPATITIS-B VACCINATION INTO THE EXPANDED PROGRAM ON IMMUNIZATION IN CHONBURI AND CHIANG-MAI PROVINCES, THAILAND

Hepatitis B (HB) immunization was introduced as part of the expanded p rogramme on immunization (EPI) in two provinces in Thailand and evalua ted over a four year period. Three doses of HB vaccine were offered to 60980 newborns at birth, 2 and 6 months of age. The overall coverage for complete HB immunization was 90.4%. Serosurveys of randomly select ed children under the age of 5 years were undertaken before and at the end of the project. Levels of HBsAg positivity were reduced by 85%, a nd there was a corresponding 70% increase in protective immunity. Thes e findings demonstrate that HB immunization can be successfully integr ated into EPI without adverse effect on coverage rates of other antige ns, and results in a marked reduction in the rate of chronic carriage of HB virus in preschool age children. (C) 1997 Elsevier Science Ltd.