Fine P E, Vynnycky E
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, UK.
Vaccine. 1998 Dec;16(20):1923-8. doi: 10.1016/s0264-410x(98)00124-8.
Exposure of populations to microbes which share antigens with pathogens can influence the apparent efficacy of vaccines. This may explain the great variation (from below 0 to 80%) observed in protection by Bacillus Calmette Guérin (BCG) against tuberculosis. This paper explores three models for the effect of such heterologous immunity, and demonstrates that: (a) if the immune responses to the microbial antigens in nature and in the vaccines differ qualitatively, there will be no effect on observed efficacy; (b) if the immune responses differ only quantitatively, the observed vaccine efficacy will be reduced, and it will be minimal when vaccine-induced and heterologous protection are of similar magnitude; and (c) if the heterologous exposure can block the vaccine action, then observed efficacy will be reduced and may even appear negative. These results provide important guidance for the interpretation of BCG's utility and for the development and evaluation of new vaccines, in particular against tuberculosis.
人群接触与病原体具有共同抗原的微生物可能会影响疫苗的表观效力。这或许可以解释观察到的卡介苗（BCG）预防结核病的保护效果存在巨大差异（从低于0%到80%）的原因。本文探讨了这种异源免疫作用的三种模型，并证明：（a）如果对自然界中微生物抗原和疫苗中微生物抗原的免疫反应在质量上存在差异，那么对观察到的效力将没有影响；（b）如果免疫反应仅在数量上存在差异，那么观察到的疫苗效力将会降低，并且当疫苗诱导的保护和异源保护程度相似时效力将降至最低；（c）如果异源接触能够阻断疫苗作用，那么观察到的效力将会降低，甚至可能呈现为负。这些结果为卡介苗效用的解读以及新疫苗（尤其是抗结核新疫苗）的研发和评估提供了重要指导。
