医学
肺结核
接种疫苗
卡介苗
儿科
星团(航天器)
整群随机对照试验
入射(几何)
随机对照试验
免疫学
外科
计算机科学
光学
物理
病理
程序设计语言
作者
Laura C. Rodrigues,Susan Martins Pereira,Sérgio Souza da Cunha,Bernd Genser,Maria Yury Ichihara,Silvana De Azevedo Brito,Miguel Aiub Hijjar,Ãlvaro A. Cruz,Clemax Couto Sant’Anna,Ana Luiza Bierrenbach,Maurício L. Barreto,Inês Dourado
出处
期刊:The Lancet
[Elsevier]
日期:2005-10-01
卷期号:366 (9493): 1290-1295
被引量:248
标识
DOI:10.1016/s0140-6736(05)67145-0
摘要
Many countries offer a second BCG vaccination to prevent tuberculosis, although there is little evidence of whether this confers additional protection. BCG vaccination is routine in Brazil but BCG revaccination procedures vary by state. We studied revaccination efficacy in two Brazilian cities with tuberculosis prevalence representative of Brazil.We did a cluster-randomised trial of the protection against tuberculosis from BCG revaccination in school-aged children who had had one BCG vaccination as infants. 767 schools in the cities of Salvador and Manaus, Brazil, participated; schools were the unit of randomisation. The study was open label with no placebo. Cases of tuberculosis were identified through record linkage to the Tuberculosis Control Programme. Revaccination status was masked during linkage and validation of cases. The incidence of tuberculosis was the primary outcome. Analysis was by intention to treat.386 schools (176,846 children) were assigned BCG revaccination and 365 (171,293 children) no revaccination. 42,053 children in the vaccine group and 47,006 in the control group were absent from school on the day of the visit and were excluded. 31,163 and 27,146, respectively were also excluded because they had no BCG scar, two or more scars, or a doubtful scar on assessment. The crude incidence of tuberculosis in the intervention group was 29.3 per 100,000 person years and in the control group 30.2 per 100,000 person-years (crude-rate ratio 0.97; 95% CI 0.76-1.28). The efficacy of BCG revaccination was 9% (-16 to 29%).Revaccination given to children aged 7-14 years in this setting does not provide substantial additional protection and should not be recommended. Follow-up is ongoing and needed to assess the effect of other factors on revaccination efficacy: time since vaccination, age at vaccination, and high or low prevalence of environmental mycobacteria.
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