Abstract：
Vaccines prevent 4-5 million deaths every year, but inequities in vaccine coverage persist among key disadvantaged subpopulations. Under-immunized subpopulations (e.g., migrants, slum residents) may be consistently missed with conventional methods for estimating immunization coverage and assessing vaccination barriers. Adaptive sampling, such as respondent-driven sampling, may offer useful strategies for identifying and collecting data from these subpopulations that are often \"hidden\" or hard-to-reach. However, use of these adaptive sampling approaches in the field of global immunization has not been systematically documented. We searched PubMed, Scopus, and Embase databases to identify eligible studies published through November 2020 that used an adaptive sampling method to collect immunization-related data. From the eligible studies, we extracted relevant data on their objectives, setting and target population, and sampling methods. We categorized sampling methods and assessed their frequencies. Twenty-three studies met the inclusion criteria out of the 3069 articles screened for eligibility. Peer-driven sampling was the most frequently used adaptive sampling method (57%), followed by geospatial sampling (30%), venue-based sampling (17%), ethnographic mapping (9%), and compact segment sampling (9%). Sixty-one percent of studies were conducted in upper-middle-income or high-income countries. Data on immunization uptake were collected in 65% of studies, and data on knowledge and attitudes about immunizations were collected in 57% of studies. We found limited use of adaptive sampling methods in measuring immunization coverage and understanding determinants of vaccination uptake. The current under-utilization of adaptive sampling approaches leaves much room for improvement in how immunization programs calibrate their strategies to reach \"hidden\" subpopulations.
摘要：
疫苗每年预防4-5百万人死亡，但在关键的弱势亚人群中,疫苗覆盖率的不平等仍然存在.免疫不足的亚群(例如，移民,贫民窟居民）可能会被常规方法所忽略，以估计免疫覆盖率和评估疫苗接种障碍。自适应采样，例如受访者驱动的抽样，可能提供有用的策略来识别和收集这些通常“隐藏”或难以到达的亚群的数据。然而,这些适应性取样方法在全球免疫领域的使用尚未有系统记录.我们搜索了PubMed,Scopus,和Embase数据库，以确定截至2020年11月发表的合格研究，这些研究使用自适应抽样方法收集免疫相关数据。从符合条件的研究中，我们提取了他们目标的相关数据，设定和目标人口，和抽样方法。我们对抽样方法进行了分类，并评估了它们的频率。在筛选合格的3069篇文章中，有23项研究符合纳入标准。同行驱动抽样是最常用的自适应抽样方法(57%)，其次是地理空间采样(30%)，基于地点的抽样(17%)，人种学制图(9%)，和紧凑的分段抽样(9%)。61%的研究是在中高收入或高收入国家进行的。在65％的研究中收集了免疫接种数据，57%的研究收集了关于免疫接种的知识和态度的数据。我们发现适应性采样方法在测量免疫覆盖率和了解疫苗接种吸收的决定因素方面的应用有限。当前对适应性采样方法的利用不足，在免疫计划如何校准其策略以达到“隐藏”亚群方面留下了很大的改进空间。
