title: Seven-year study of hepatitis B vaccine efficacy in infants from an endemic area (Senegal).
abstract: A booster dose of hepatitis B vaccine was given to 143 children in whom hepatitis B had not developed 1 year after initial vaccination. Over the next six years the incidence of hepatitis B in this group was 1.5% per year compared with 11.5% per year in a similar group of unvaccinated children. In the first 4 years the protective efficacy of the vaccine was 100%, but during the 5th and 6th years it fell to 67%. For maximum protection a second booster is needed, 5 years after the first.
mesh_terms: D002353:Carrier State / Q000517:prevention & control; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006509:Hepatitis B / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000032:analysis; D017325:Hepatitis B Vaccines; D006801:Humans; D007117:Immunization, Secondary; D007223:Infant; D008297:Male; D012675:Senegal; D013997:Time Factors; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage*
chemical_list: D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D014761:Viral Hepatitis Vaccines