Melegaro A, Edmunds W J
Modelling and Economics Unit, Health Protection Agency, Communicable Disease Surveillance Centre, 61 Colindale Avenue, London NW9 5EQ, UK.
Vaccine. 2004 Oct 22;22(31-32):4203-14. doi: 10.1016/j.vaccine.2004.05.003.
To establish whether universal vaccination of infants with the pneumococcal conjugate vaccine is likely to be cost-effective from the perspective of the health care provider (NHS).
Two hypothetical cohorts--one vaccinated and one unvaccinated--were followed over their lifetime, and the expected net costs and benefits (measured in terms of life-years and quality adjusted life years (QALY) gained) were compared in the two cohorts. The impact of indirect effects of the vaccine, such as herd immunity and serotype replacement, were investigated and their relative importance was assessed by performing univariate sensitivity analysis and multivariate Monte Carlo simulations.
Under base-case assumptions (no herd immunity and no serotype replacement) the programme is not expected to be cost-effective from the NHS perspective at the current price of the vaccine (assumed 30 pounds per dose, three-dose programme). A reduction of the cost of the vaccine to half of its current level could bring the cost per QALY gained within normally acceptable ranges. If the burden of disease is significantly underestimated by current surveillance systems, then the cost per QALY gained approaches acceptable levels at the current vaccine price. Herd immunity may substantially reduce the burden of pneumococcal disease, particularly of pneumonia among the elderly, leading to a significant improvement in the cost per life year and QALY gained. Serotype replacement would partly offset these benefits, although only with a complete substitution of vaccine types with non-vaccine types and a low level of herd immunity, would pneumococcal vaccination programme would not be cost-effective.
Conclusions on the cost-effectiveness of pneumococcal conjugate vaccine are sensitive to assumptions regarding the current burden of pneumococcal disease and the future impact that vaccination will have in the unvaccinated and on the future serotype distribution. This study quantifies, for the first time, how these indirect effects may change the cost-effectiveness of pneumococcal vaccination.
从医疗服务提供者(英国国家医疗服务体系)的角度确定对婴儿普遍接种肺炎球菌结合疫苗是否具有成本效益。
对两个假设队列——一个接种疫苗,一个未接种疫苗——进行终生跟踪,并比较两个队列的预期净成本和效益(以获得的生命年和质量调整生命年(QALY)衡量)。研究了疫苗间接效应的影响,如群体免疫和血清型替换,并通过单变量敏感性分析和多变量蒙特卡洛模拟评估了它们的相对重要性。
在基本假设(无群体免疫和无血清型替换)下,从英国国家医疗服务体系的角度来看,按照当前疫苗价格(假设每剂30英镑,三剂接种方案),该计划预计不具有成本效益。将疫苗成本降低至当前水平的一半可使每获得一个QALY的成本处于正常可接受范围内。如果当前监测系统严重低估了疾病负担,那么按照当前疫苗价格,每获得一个QALY的成本接近可接受水平。群体免疫可能会大幅降低肺炎球菌疾病负担,尤其是老年人中的肺炎负担,从而显著改善每生命年和每获得一个QALY的成本。血清型替换会部分抵消这些益处,不过只有在疫苗类型完全被非疫苗类型替代且群体免疫水平较低的情况下,肺炎球菌疫苗接种计划才不具有成本效益。
关于肺炎球菌结合疫苗成本效益的结论对以下假设敏感:肺炎球菌疾病的当前负担、疫苗接种对未接种者的未来影响以及未来血清型分布。本研究首次量化了这些间接效应如何可能改变肺炎球菌疫苗接种的成本效益。