An ancillary care policy in a vaccine trial conducted in a resource-constrained setting: evaluation and policy recommendations

Introduction
Clear guidelines to implement ancillary care (AC) in clinical trials conducted in resource-constrained settings are lacking. Here, we evaluate an AC policy developed for a vaccine trial in the Democratic Republic of the Congo and formulate policy recommendations.

Methods
To evaluate the AC policy, we performed a longitudinal cohort study, nested in an open-label, single-centre, randomised Ebola vaccine trial conducted among healthcare personnel. Participants’ demographic information, residence distance to the study site and details on the financial and/or medical support provided for any (serious) adverse events ((S)AE) were combined and analysed. To assess the feasibility of the AC policy, an expenditure analysis of the costs related to AC support outcomes was performed.

Results
Enrolment in this evaluation study started on 29 November 2021. The study lasted 11 months and included 655 participants from the Ebola vaccine trial. In total, 393 participants used the AC policy, mostly for AE management (703 AE and 94 SAE) via medication provided by the study pharmacy (75.3%). Men had a 35.2% (95% CI 4.0% to 56.6%) lower likelihood of reporting AE compared with women. Likewise, this was 32.3% lower (95% CI 5.8% to 51.4%) for facility-based compared with community-based healthcare providers. The daily AE reporting was 78.8% lower during the passive vs the active trial stage, and 97.4% lower during unscheduled vs scheduled visits (p<0.001). Participants living further than 10 km from the trial site more frequently reported the travel distance as a reason for not using the policy (p<0.04). In practice, only 1.1% of the operational trial budget was used for AC policy support.

Conclusion
The trial design, study population and local health system impacted the use of the AC policy. Nonetheless, the AC policy implementation in this remote and resource-constrained setting was feasible, had negligible budgetary implications and contributed to participants’ healthcare options and well-being.