Long-term efficacy of plasma-derived hepatitis B vaccine: a 15-year follow-up study among Chinese children.
To determine necessity and timing of booster of hepatitis B vaccine, we need to observe the duration of its protection. We report the results of a 15-year follow-up of a cohort of 649 children who participated a randomized, double blind, placebo-controlled trial on a plasma-derived hepatitis B vaccine in 1982. During the 15 years after vaccination, more vaccinated children had anti-HBs of 10 S/N ratios or over, compared with the controls, at all nine observations. At 15 years 50.0% (26/52) of the participants studied in the vaccinated group and 33.3% of the tested controls (18/54) retained anti-HBs levels of S/N ratios> or =10 (P < 0.09). However, since 5 years after vaccination, median S/N ratios of anti-HBs among the vaccinated children with detectable anti-HBs were lower than those of the controls except that detected at 15 years. 16.7% (9/54) of the tested children in the control group were HBsAg positive at 15 years after vaccination, in comparison with 1.9% (1/52) of the tested children in the vaccinated (P < 0.02). 28 chronic HBsAg carriers were identified in the control cohort over the 15 years, whereas only 1 case was noted in the vaccinated group (8.2% vs. 0.3%, P < 0.00001), corresponding to an efficacy of 96%.
Institute of Basic Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China. susuliao@mx.cei.gov.cn
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D004311:Double-Blind Method; D005500:Follow-Up Studies; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006801:Humans; D007223:Infant; D013997:Time Factors; D014611:Vaccination
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines