Adamu Abdu A, Jalo Rabiu I, Masresha Balcha G, Ndwandwe Duduzile, Wiysonge Charles S
Polio Eradication Programme, World Health Organization Region Office for Africa, Djoue, Brazzaville P.O. Box 06, Congo.
Vaccine-Preventable Diseases Programme, World Health Organization Regional Office for Africa, Djoue, Brazzaville P.O. Box 06, Congo.
Vaccines (Basel). 2024 Aug 8;12(8):896. doi: 10.3390/vaccines12080896.
The second dose of measles-containing vaccines (MCV2) has significant programmatic relevance in the current immunisation landscape because it serves as both an opportunity to reduce measles immunity gaps and strengthen second year of life vaccination platforms. However, MCV2 coverage remains suboptimal across countries in the World Health Organization (WHO) African Region and this puts a significant number of children at risk of morbidity and mortality from measles despite the availability of an effective vaccine. There is an urgent need to strengthen the implementation of MCV2 but this requires a thorough and systematic understanding of contextual factors that influence it. The literature that describes the determinants of implementation of MCV2 in a manner that adequately accounts for the complexity of the implementation context is scarce. Therefore, the purpose of this rapid review was to explore the implementation determinants of MCV2 in the WHO African Region using systems thinking. Literature search in two databases (PubMed and Google Scholar) were conducted. After screening, a total of 17 eligible articles were included in the study. Thematic analysis of extracted data was performed to identify the implementation determinants, after which they were mapped using the Consolidated Framework for Implementation Research (CFIR). A causal loop diagram (CLD) was used to illustrate the linkages between identified determinants. We found 44 implementation determinants across the five CFIR domains, i.e., innovation, outer setting, inner setting, individual, and implementation process. The majority of identified determinants are within the individual domain followed by the inner setting domain. The CLD showed that multiple contingent connections and feedback relationships exist between the identified implementation determinants within and across CFIR domains. The linkages between the implementation determinants revealed three balancing and reinforcing loops each. The findings suggest that implementation determinants of second-dose measles vaccination in the WHO African Region are complex, with multiple interconnections and interdependencies, and this insight should guide subsequent policies. There is an urgent need for further implementation research with embedded CLD in specific settings to inform the design of tailored systemic strategies to improve the implementation effectiveness of MCV2.
含麻疹疫苗的第二剂（MCV2）在当前免疫格局中具有重要的规划意义，因为它既是缩小麻疹免疫差距的契机，也是加强一岁儿童疫苗接种平台的机会。然而，世界卫生组织（WHO）非洲区域各国的MCV2覆盖率仍未达到最佳水平，尽管有有效的疫苗，但这仍使大量儿童面临麻疹发病和死亡的风险。迫切需要加强MCV2的实施，但这需要对影响其实施的背景因素有全面系统的了解。以充分考虑实施背景复杂性的方式描述MCV2实施决定因素的文献很少。因此，本快速综述的目的是运用系统思维探索WHO非洲区域MCV2的实施决定因素。我们在两个数据库（PubMed和谷歌学术）中进行了文献检索。筛选后，共有17篇符合条件的文章纳入研究。对提取的数据进行主题分析以确定实施决定因素，之后使用实施研究综合框架（CFIR）对其进行映射。因果循环图（CLD）用于说明已确定决定因素之间的联系。我们在CFIR的五个领域，即创新、外部环境、内部环境、个人和实施过程中发现了44个实施决定因素。大多数已确定的决定因素在个人领域，其次是内部环境领域。CLD显示，CFIR领域内和跨领域的已确定实施决定因素之间存在多个偶然联系和反馈关系。实施决定因素之间的联系分别揭示了三个平衡和强化循环。研究结果表明，WHO非洲区域第二剂麻疹疫苗接种的实施决定因素很复杂，存在多重相互联系和相互依存关系，这一见解应指导后续政策制定。迫切需要在特定环境中开展进一步的实施研究，并嵌入CLD，以为量身定制的系统策略设计提供信息，以提高MCV2的实施效果。
