Interview transcriptions.

Effective spontaneous AEFI reporting is the first step to ensuring vaccine safety. Half of the global population lives in countries with weak vaccine safety monitoring systems, especially in the African, Eastern Mediterranean, and Western Pacific regions. Further, Immunisation services have been upscaled without commensurate effective AEFI surveillance systems. Hence, this study aims to comprehensively investigate the impediments to an effective AEFI surveillance system. Given the programmatic and regulatory implications, understanding these impediments would facilitate the development and implementation of policies and strategies to strengthen the AEFI surveillance system in Nigeria. A qualitative research design (using a grounded theory approach) was employed by conducting ten key informant interviews and two Focus Group Discussion sessions among the study population to identify the barriers impeding optimal AEFI surveillance and documentation in Nigeria. This study found that the AEFI surveillance system is in place in Nigeria. However, its functionality is sub-optimal, and the potential capacity is yet to be fully harnessed due to health systems and socio-ecological impediments. The identified impediments are human-resource-related issues- knowledge gaps; limited training; lack of designated officers for AEFI; excessive workload; poor supportive supervision and attitudinal issues; caregiver’s factor; governance and leadership- moribund AEFI committee; lack of quality supervisory visit and oversight and weak implementation of AEFI policy guidance. Others include funding and logistics issues- no dedicated budget provision and weak referral mechanism; insecurity; socio-economic and infrastructural deficits- poverty, geographical barriers, limited ICT skills, and infrastructure; and poor feedback and weak community engagement by the health workers. Findings from this study provide empirical evidence and serve as an advocacy tool for vaccine pharmacovigilance strengthening in Nigeria. Addressing the impediments requires health system strengthening and a whole-of-the-society approach to improve vaccine safety surveillance, restore public confidence and promote vaccine demand, strengthen PHC services, and contribute to attaining UHC and SDGs.

有效的自发上报预防接种后不良事件（Adverse Events Following Immunization, AEFI）是保障疫苗安全的首要环节。全球有半数人口居住在疫苗安全监测体系薄弱的国家，尤以非洲、东地中海及西太平洋地区为甚。此外，免疫规划服务规模持续扩容，但与之匹配的高效AEFI监测体系却未能同步建立。
有鉴于此，本研究旨在全面探究制约高效AEFI监测体系构建的各类障碍因素。考虑到其对免疫规划工作与监管体系的多重影响，明确这些障碍将有助于尼日利亚制定并推行强化AEFI监测体系的相关政策与策略。
本研究采用质性研究设计，运用扎根理论法，通过对研究对象开展10次关键知情人访谈与2次焦点小组讨论（Focus Group Discussion, FGD），以识别阻碍尼日利亚境内AEFI最优监测与记录工作的各类障碍。
本研究发现，尼日利亚已搭建起AEFI监测体系，但其运行效能未达最优，且受卫生系统与社会生态层面的障碍制约，其潜在能力尚未得到充分发挥。经识别，障碍因素涵盖以下类别：其一为人力资源相关问题，包括知识缺口、培训资源不足、未配备专职AEFI管理人员、工作负荷过重、支持性督导匮乏、态度偏差以及照料者因素；其二为治理与领导力层面问题，包括AEFI委员会形同虚设、优质督导与监管缺位、AEFI政策指南执行不力；其三为经费与后勤保障问题，即无专项预算拨款、转诊机制薄弱；其四为安全保障不足；其五为社会经济与基础设施缺陷，包括贫困、地理阻隔、信息与通信技术（Information and Communication Technology, ICT）技能与设施匮乏；此外还包括卫生工作者反馈机制不完善、社区参与度低下等问题。
本研究结果可为尼日利亚强化疫苗药物警戒工作提供实证依据与宣传倡导工具。破解上述障碍需强化卫生系统建设，并采用全社会协同的整体施策模式，以提升疫苗安全监测水平、重塑公众信任、提振疫苗接种需求、强化初级卫生保健（Primary Health Care, PHC）服务，并助力实现全民健康覆盖（Universal Health Coverage, UHC）与可持续发展目标（Sustainable Development Goals, SDGs）。