Strengthening Post-Market Vaccine Safety Surveillance Globally: An Interpretive Description Study from Kenya, South Africa, and Canada

Abstract Background Post-market vaccine safety surveillance and research are essential to detect and evaluate rare adverse events following immunization (AEFIs) not identified in pre-licensure clinical trials, such as myocarditis post-COVID-19 vaccination. AEFI surveillance infrastructure varies between jurisdictions. Factors that enable or hinder AEFI investigation across diverse settings are not well understood. Objective To examine clinical, social, and structural/system factors that enable AEFI case identification, reporting, data and biosample collection in high-income countries (HICs) and low-and middle-income countries (LMICs). Methods We conducted a qualitative study informed by Interpretive Description in Kenya, South Africa, and Canada. Participants were recruited using purposive and snowball sampling from three groups: (1) key informants with leadership roles in AEFI surveillance and research, (2) healthcare workers, research and laboratory staff involved in AEFI investigation and research, and (3) past participants in vaccine studies. Data were collected through semi-structured interviews and focus group discussions. Thematic analysis was conducted. Results Eighteen key informants, 47 healthcare workers and research staff, and 27 past research participants were enrolled. Facilitators and barriers were identified across two domains: AEFI surveillance and investigation, and vaccine safety research participation. AEFI surveillance and investigation were shaped by trust in system responsiveness, beliefs and awareness around AEFI reporting, digital innovation, and implementation gaps. Research participation was shaped by altruism and social influence, logistics and research infrastructure, and institutional policies and privacy. Facilitators to AEFI surveillance and research included established policies and procedures for AEFI surveillance, digital tools, emphatic communication, and convenient research processes. Barriers included limitations in workforce capacity, diagnostic testing and funding (especially in LMICs), and cumbersome research approval processes. Conclusions Findings underscore the need for both globally harmonized standards and locally tailored strategies to support vaccine safety surveillance and research in LMICs and HICs that are patient/participant-centered and include sustainable investments in infrastructure and workforce capacity.