Data from: Global yellow fever vaccination coverage from 1970 to 2016: an adjusted retrospective analysis

Background: Substantial outbreaks of yellow fever in Angola and Brazil in the past 2 years, combined with global shortages in vaccine stockpiles, highlight a pressing need to assess present control strategies. The aims of this study were to estimate global yellow fever vaccination coverage from 1970 through to 2016 at high spatial resolution and to calculate the number of individuals still requiring vaccination to reach population coverage thresholds for outbreak prevention. Methods: For this adjusted retrospective analysis, we compiled data from a range of sources (eg, WHO reports and health-service-provider registeries) reporting on yellow fever vaccination activities between May 1, 1939, and Oct 29, 2016. To account for uncertainty in how vaccine campaigns were targeted, we calculated three population coverage values to encompass alternative scenarios. We combined these data with demographic information and tracked vaccination coverage through time to estimate the proportion of the population who had ever received a yellow fever vaccine for each second level administrative division across countries at risk of yellow fever virus transmission from 1970 to 2016. Findings: Overall, substantial increases in vaccine coverage have occurred since 1970, but notable gaps still exist in contemporary coverage within yellow fever risk zones. We estimate that between 393·7 million and 472·9 million people still require vaccination in areas at risk of yellow fever virus transmission to achieve the 80% population coverage threshold recommended by WHO; this represents between 43% and 52% of the population within yellow fever risk zones, compared with between 66% and 76% of the population who would have required vaccination in 1970. Interpretation: Our results highlight important gaps in yellow fever vaccination coverage, can contribute to improved quantification of outbreak risk, and help to guide planning of future vaccination efforts and emergency stockpiling.研究背景：过去两年安哥拉与巴西暴发大规模黄热病疫情，叠加全球疫苗储备短缺问题，凸显了评估当前防控策略的迫切需求。本研究旨在以高空间分辨率估算1970年至2016年全球黄热病疫苗接种覆盖率，并计算仍需接种疫苗以达到疫情防控所需人群接种阈值的人数。 研究方法：本项经调整的回顾性分析整合了1939年5月1日至2016年10月29日期间，来自多类来源（如世界卫生组织[WHO]报告、卫生服务提供者登记册）的黄热病疫苗接种活动相关数据。为考量疫苗接种行动靶向策略的不确定性，我们计算了三种人群接种覆盖率数值，以涵盖不同假设情景。我们将上述数据与人口统计信息相结合，并随时间追踪疫苗接种覆盖率，以估算1970年至2016年间，黄热病病毒传播风险国家内各二级行政区曾接种黄热病疫苗的人群比例。 研究结果：整体而言，自1970年以来疫苗接种覆盖率已实现大幅提升，但黄热病风险区域内的当前接种覆盖率仍存在显著缺口。经估算，黄热病病毒传播风险区域内仍有3.937亿至4.729亿人口需接种疫苗，才能达到世界卫生组织（WHO）推荐的80%人群接种阈值；该人群占黄热病风险区域总人口的43%至52%，而1970年时需接种疫苗的人群占比为66%至76%。 研究讨论：本研究结果凸显了黄热病疫苗接种覆盖率存在的显著缺口，可为提升疫情风险量化水平提供支撑，并有助于指导未来疫苗接种规划与应急储备工作。