National Routine Adult Immunization Programs among World Health Organization Member States: An Assessment of Health Systems to Deploy Future SARS-CoV-2 Vaccines

Introduction: As the SARS-CoV-2 pandemic disproportionately affects older adults, future pandemic vaccine response will rely on existing adult immunization infrastructures. Methods: We evaluated the 2018 WHO/UNICEF Joint Reporting Form on Immunization for country reports on adult immunization programs. We described countries with programs and used multivariable regression to identify independent factors associated with having them. Results: Of 194 WHO Member States, 120 (62%) reported having any adult vaccination program. The Americas and Europe had the most adult immunization programs, most commonly Hepatitis B and influenza vaccines (>45% and >90% of countries). Africa and South-East Asia had the fewest adult immunization programs, with <11% of countries reporting any adult immunization programs for influenza or hepatitis vaccines, and none for pneumococcal vaccines. In bivariate analyses, high- or upper-middle income, introduction of new or underused vaccines, having achieved pediatric vaccine coverage goals, and meeting National Immunization Technical Advisory Groups basic functional indicators were significantly associated (p<0.001) with having any adult immunization programs. In multivariable analyses, the factor most strongly associated with adult immunization programs was country income, with high- or upper-middle income countries significantly more likely to report having a program (aOR 19.3, 95% CI 6.5, 57.7). Discussion: That 38% of countries lack functional platforms for adult immunization has major implications for future SARS-CoV-2 vaccine deployment. Systems for vaccine storage and handling, delivery, and waste management for adult immunization do not exist in much of the world. Developing countries should strengthen immunization programs to reach adults with SARS-CoV-2 vaccines when they become available.

引言：由于新冠病毒大流行对老年人的影响尤为严重，未来大流行疫苗接种工作将依赖现有的成人免疫基础设施。 方法：我们评估了2018年世卫组织/联合国儿童基金会联合免疫报告表中各国关于成人免疫规划的报告。我们对有相关规划的国家进行了描述，并使用多变量回归来确定与拥有这些规划相关的独立因素。 结果：在世卫组织194个成员国中，120个（62%）报告称有任何成人疫苗接种规划。美洲和欧洲的成人免疫规划最多，最常见的是乙肝和流感疫苗（分别有>45%和>90%的国家）。非洲和东南亚的成人免疫规划最少，<11%的国家报告有针对流感或乙肝疫苗的任何成人免疫规划，且没有针对肺炎球菌疫苗的规划。在双变量分析中，高收入或中高收入、引入新的或未充分利用的疫苗、已实现儿童疫苗覆盖目标以及符合国家免疫技术咨询小组基本功能指标，都与拥有任何成人免疫规划显著相关（p<0.001）。在多变量分析中，与成人免疫规划关联最强的因素是国家收入，高收入或中高收入国家报告拥有规划的可能性显著更高（调整比值比为19.3，95%置信区间为6.5 - 57.7）。 讨论：38%的国家缺乏成人免疫的有效平台，这对未来新冠病毒疫苗的部署具有重大影响。世界上许多地方都不存在用于成人免疫的疫苗储存和处理、配送以及废弃物管理系统。发展中国家应加强免疫规划，以便在新冠病毒疫苗可用时为成年人接种。