Lo Nathan C, Hotez Peter J
MD/PhD Candidate, Division of Epidemiology, Stanford University School of Medicine, Stanford, California.
Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston.
JAMA Pediatr. 2017 Sep 1;171(9):887-892. doi: 10.1001/jamapediatrics.2017.1695.
Routine childhood vaccination is declining in some regions of the United States due to vaccine hesitancy, which risks the resurgence of many infectious diseases with public health and economic consequences. There are ongoing policy debates on the state and national level, including legislation around nonmedical (personal-belief) exemptions for childhood vaccination and possibly a special government commission on vaccine safety, which may affect vaccine coverage.
To estimate the number of measles cases in US children and the associated economic costs under scenarios of different levels of vaccine hesitancy, using the case example of measles, mumps, and rubella (MMR) vaccination and measles.
DESIGN, SETTING, AND PARTICIPANTS: Publicly available data from the US Centers for Disease Control and Prevention were used to simulate county-level MMR vaccination coverage in children (age 2-11 years) in the United States. A stochastic mathematical model was adapted for infectious disease transmission that estimated a distribution for outbreak size as it relates to vaccine coverage. Economic costs per measles case were obtained from the literature. The predicted effects of increasing the prevalence of vaccine hesitancy as well as the removal of nonmedical exemptions were estimated. The model was calibrated to annual measles cases in US children over recent years, and the model prediction was validated using an independent data set from England and Wales.
Annual measles cases in the United States and the associated public sector costs.
A 5% decline in MMR vaccine coverage in the United States would result in an estimated 3-fold increase in measles cases for children aged 2 to 11 years nationally every year, with an additional $2.1 million in public sector costs. The numbers would be substantially higher if unvaccinated infants, adolescents, and adult populations were also considered. There was variation around these estimates due to the stochastic elements of measles importation and sensitivity of some model inputs, although the trend was robust.
This analysis predicts that even minor reductions in childhood vaccination, driven by vaccine hesitancy (nonmedical and personal belief exemptions), will have substantial public health and economic consequences. The results support an urgent need to address vaccine hesitancy in policy dialogues at the state and national level, with consideration of removing personal belief exemptions of childhood vaccination.
由于疫苗犹豫,美国一些地区的儿童常规疫苗接种率正在下降,这有可能导致许多传染病卷土重来,带来公共卫生和经济后果。州和国家层面正在进行政策辩论,包括围绕儿童疫苗接种非医疗(个人信仰)豁免的立法,以及可能设立一个关于疫苗安全的特别政府委员会,这些可能会影响疫苗接种覆盖率。
以麻疹、腮腺炎和风疹(MMR)疫苗接种及麻疹为例,估计在美国不同程度疫苗犹豫情况下美国儿童麻疹病例数及相关经济成本。
设计、背景和参与者:利用美国疾病控制与预防中心公开的数据,模拟美国2至11岁儿童的县级MMR疫苗接种覆盖率。采用一个适用于传染病传播的随机数学模型,估计与疫苗接种覆盖率相关的疫情规模分布。从文献中获取每例麻疹病例的经济成本。估计了疫苗犹豫率上升以及取消非医疗豁免的预测影响。该模型根据美国近年来儿童年度麻疹病例进行校准,并使用来自英格兰和威尔士的独立数据集对模型预测进行验证。
美国年度麻疹病例数及相关公共部门成本。
美国MMR疫苗接种覆盖率下降5%,预计全国2至11岁儿童的麻疹病例数将每年增加约3倍,公共部门成本将增加210万美元。如果也考虑未接种疫苗的婴儿、青少年和成人人群,数字将大幅更高。由于麻疹输入的随机因素和一些模型输入的敏感性,这些估计存在差异,尽管趋势是稳健的。
该分析预测,即使由疫苗犹豫(非医疗和个人信仰豁免)导致的儿童疫苗接种率略有下降,也将产生重大的公共卫生和经济后果。结果支持迫切需要在州和国家层面的政策对话中解决疫苗犹豫问题,考虑取消儿童疫苗接种的个人信仰豁免。