Department of Pharmacy, University of Groningen, the Netherlands.
Clin Ther. 2010 Aug;32(8):1479-95. doi: 10.1016/j.clinthera.2010.07.017.
Pertussis is a highly contagious respiratory disease. Despite a high rate of vaccine coverage through the Dutch national immunization program, the incidence of pertussis remains high in the Netherlands and the risk of infection continues. Because pertussis is most severe in unimmunized infants and infants who have only received some of the recommended doses, new pertussis immunization strategies should be considered to protect this vulnerable population.
This study was designed to estimate the cost-effectiveness of 3 new immunization strategies for possible addition to the current Dutch national immunization program: immunization of the infant at birth, immunization of the parents immediately after birth of the child (cocooning), and maternal immunization during the third trimester of pregnancy.
A literature search was performed in the PubMed database for articles published in English, German, and Dutch using the following terms: pertussis, whooping cough, vaccination strategies, maternal immunization, cocooning, at birth, vaccine efficacy, mortality, underreporting, prevalence, incidence, and cost-effectiveness. A decision-tree model was developed for this analysis, and data on pertussis morbidity and costs were collected consistently for different age groups (infants <1 year of age and adults 25 to 34 years of age). The size of the infant cohort was set at 200,000 to approximate previous Dutch birth cohorts. The size of the adult cohort was set at 401,380 parents for the cocooning strategy and 201,380 mothers for the maternal immunization strategy. Health benefits (quality-adjusted life-years [QALYs]) and costs were estimated in both cohorts for each of the 3 immunization strate- gies. Incremental cost-effectiveness ratios were calculated from both a payer's and a societal perspective. The robustness of the results was determined through sensitivity analysis.
In the base-case analysis, cocooning and maternal immunization were found to be effective in reducing the incidence of pertussis among infants (123 and 174 infant cases were expected to be prevented, respectively). Furthermore, cocooning and maternal immunization were estimated to be cost-effective from a payer's perspective (euro4600 [US $6400]/QALY and euro3500 [$4900]/QALY, respectively) and even cost-saving from a societal perspective (savings of up to euro7200 [$10,100] and euro5000 [$7000], respectively). Sensitivity analyses revealed that favorable cost-effectiveness was generally robust. In the sensitivity analysis, the cost-effectiveness of cocooning and maternal immunization was mostly sensitive for changes in assumptions on underreporting (200-fold increase in reported number of symptomatic cases) of pertussis disease and infection. With no underreporting, the ICER was estimated at euro211,900 ($296,700)/QALY for cocooning and euro81,600 ($114,200)/QALY for maternal immunization from a payer's perspective. However, even at much lower levels of underreporting (20- to 30-fold increase in incidence), cost-effectiveness remained favorable. The cost-effectiveness of the third strategy, at-birth immunization, was highly unfavorable (euro329,900 [$461,900]/QALY from a payer's perspective and euro330,100 [$462,100]/ QALY from a societal perspective).
This study estimated that the addition of cocooning or maternal immunization to the current Dutch national immunization program likely would be cost-effective or even cost-saving. These estimates were mainly due to reduction in the number of cases among parents, which are likely to be mild and therefore would largely remain unreported. Immunization at birth was not a cost-effective strategy. Cocooning was the most expensive intervention to implement; however, it resulted in the highest number of QALYs gained (mainly in adults). Maternal immunization would offer better protection of infants, due to maternally acquired antibodies.
百日咳是一种高度传染性的呼吸道疾病。尽管荷兰国家免疫计划的疫苗接种率很高，但在荷兰，百日咳的发病率仍然很高，感染的风险仍然存在。由于百日咳在未免疫的婴儿和仅接受部分推荐剂量的婴儿中最为严重，因此应考虑新的百日咳免疫策略，以保护这一脆弱人群。
本研究旨在估计 3 种新免疫策略的成本效益，这些策略可能会被添加到目前的荷兰国家免疫计划中：婴儿出生时免疫、婴儿出生后父母立即免疫（围产期免疫）和孕妇在妊娠晚期免疫。
在 PubMed 数据库中，使用以下术语进行了英语、德语和荷兰语的文献搜索：百日咳、白喉、疫苗接种策略、孕妇免疫、围产期免疫、出生时、疫苗效力、死亡率、漏报、流行率、发病率和成本效益。为这项分析开发了一个决策树模型，并为不同年龄组（<1 岁的婴儿和 25 至 34 岁的成年人）一致收集了百日咳发病率和成本的数据。将婴儿队列的规模设定为 20 万，以近似于以前的荷兰出生队列。将成人队列的规模设定为 401380 名父母（围产期免疫策略）和 201380 名母亲（孕妇免疫策略）。在两个队列中，为每一种免疫策略估算了健康效益（质量调整生命年[QALY]）和成本。从支付者和社会角度计算了增量成本效益比。通过敏感性分析确定了结果的稳健性。
在基本情况下，围产期免疫和孕妇免疫被发现可以有效降低婴儿的百日咳发病率（分别预期可以预防 123 和 174 例婴儿病例）。此外，围产期免疫和孕妇免疫从支付者的角度来看是具有成本效益的（欧元 4600[6400 美元]/QALY 和欧元 3500[4900 美元]/QALY，分别），甚至从社会的角度来看是具有成本效益的（节省最多可达欧元 7200[10100 美元]和欧元 5000[7000 美元]，分别）。敏感性分析表明，有利的成本效益通常是稳健的。在敏感性分析中，围产期免疫和孕妇免疫的成本效益对百日咳疾病和感染的报告病例数（报告的有症状病例数增加 200 倍）的漏报情况变化较为敏感。如果没有漏报，从支付者的角度来看，围产期免疫的 ICER 估计为欧元 211900（296700 美元）/QALY，孕妇免疫的 ICER 估计为欧元 81600（114200 美元）/QALY。然而，即使在漏报率较低的情况下（发病率增加 20-30 倍），成本效益仍然是有利的。第三种策略，出生时免疫，成本效益非常不利（从支付者的角度来看，欧元 329900[461900 美元]/QALY，从社会的角度来看，欧元 330100[462100 美元]/QALY）。
本研究估计，将围产期免疫或孕妇免疫添加到目前的荷兰国家免疫计划中，可能具有成本效益，甚至具有成本效益。这些估计主要是由于父母中病例数量的减少，这些病例很可能是轻微的，因此在很大程度上仍未报告。出生时免疫不是一种具有成本效益的策略。围产期免疫是最昂贵的干预措施；然而，它带来了最高数量的 QALY 获益（主要在成年人中）。孕妇免疫将为婴儿提供更好的保护，因为它可以通过母体获得抗体。
