Wilson M E
Harvard Medical School and the Harvard School of Public Health, Boston, and Division of Infectious Diseases, Mount Auburn Hospital, Cambridge, MA 02238, USA.
Clin Infect Dis. 2000 Jun;30 Suppl 3:S262-5. doi: 10.1086/313886.
Bacille Calmette-Guérin (BCG) vaccine, a live vaccine developed to prevent tuberculosis (TB), has been given to billions of persons over more than 7 decades. Studies of the efficacy of BCG vaccine have had widely divergent results, underscoring the complexity of the biology and immunology of TB. The long duration of TB infection, the heterogeneity of its clinical expression, and lack of inexpensive, reliable markers of infection and disease have made it difficult to study the impact of a vaccine, especially in resource-poor areas. A meta-analysis of data from trials of BCG vaccine found that studies conducted at sites that are a greater distance from the equator are associated with better vaccine efficacy, a finding that needs fuller study. BCG vaccine trials with higher validity scores showed higher rates of protection. Ongoing changes, including human immunodeficiency virus infection and demographic shifts, should be considered when developing trials of future vaccines. Analyses of past studies of BCG vaccine can identify sources of variation that may guide the design of studies of new vaccines. Rigorous study design and new tools are needed if studies are to provide clear, useful answers about new vaccines.
卡介苗（BCG）是一种为预防结核病（TB）而研发的活疫苗，在过去七十多年里已接种数十亿人。卡介苗疫苗效力的研究结果差异很大，这凸显了结核病生物学和免疫学的复杂性。结核病感染持续时间长、临床表现异质性大，且缺乏廉价、可靠的感染和疾病标志物，使得研究疫苗的影响变得困难，尤其是在资源匮乏地区。对卡介苗疫苗试验数据的一项荟萃分析发现，在距离赤道较远地区开展的研究中，疫苗效力更佳，这一发现尚需更充分的研究。效度评分较高的卡介苗疫苗试验显示出更高的保护率。在开展未来疫苗试验时，应考虑包括人类免疫缺陷病毒感染和人口结构变化在内的持续变化。对过去卡介苗疫苗研究的分析可以确定可能指导新疫苗研究设计的变异来源。若要研究为新疫苗提供清晰、有用的答案，就需要严谨的研究设计和新工具。
