al-Kassimi F A, al-Hajjaj M S, al-Orainey I O, Bamgboye E A
Medical Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
Am J Respir Crit Care Med. 1995 Nov;152(5 Pt 1):1575-8. doi: 10.1164/ajrccm.152.5.7582297.
A case-control study was conducted in Saudi Arabia, where the same strain of BCG has been used and surveys had shown that up to 88% of vaccinated children remain tuberculin negative. Active cases were obtained by surveying the seven tuberculosis centers in 1 yr. Control subjects were obtained from a nationwide survey of normal individuals. Vaccination in both groups was ascertained by history and BCG scar. Relative risk of contracting active tuberculosis in the vaccinated versus unvaccinated and protection was calculated. Protection was as follows: age group 5 to 14 yr, 82% (55 to 93%); age group 15 to 24 yr, 67% (55 to 77%); and age group 25 to 34 yr, 20% (-6 to 37%). We document the uninterrupted record of protection by BCG administered in the neonatal period and discuss the significance of vaccination timing. We concur with other studies that protection lapsed after about 20 yr. More importantly, this is the first large study that documents a lack of tuberculin sensitivity despite protection. This challenges the view that sensitization is essential for protection and supports the "two-pathway" theory that BCG vaccination could trigger either protective (Lister type) or antagonistic (tuberculin or Koch type) reactions and that the most protective vaccines would have little tuberculin-sensitizing effect because the two pathways are competitive.
在沙特阿拉伯进行了一项病例对照研究，该国使用的是同一株卡介苗，调查显示高达88%的接种儿童结核菌素检测仍呈阴性。通过对7个结核病中心进行为期1年的调查获取活动性病例。对照对象来自对全国正常个体的调查。通过询问病史和查看卡介苗疤痕来确定两组的疫苗接种情况。计算接种疫苗组与未接种疫苗组感染活动性结核病的相对风险及保护率。保护率如下：5至14岁年龄组为82%（55%至93%）；15至24岁年龄组为67%（55%至77%）；25至34岁年龄组为20%（-6%至37%）。我们记录了新生儿期接种卡介苗后的持续保护记录，并讨论了接种时间的重要性。我们认同其他研究的观点，即保护作用在约20年后消失。更重要的是，这是第一项记录了尽管有保护作用但仍缺乏结核菌素敏感性的大型研究。这对致敏作用对保护至关重要的观点提出了挑战，并支持了“双途径”理论，即卡介苗接种可能引发保护性（李斯特菌型）或拮抗性（结核菌素或科赫菌型）反应，且最具保护作用的疫苗对结核菌素的致敏作用很小，因为这两种途径相互竞争。
