Parental motivations and perceived barriers to participating in pediatric vaccine clinical trials: Findings from the OCV-S trial in Nepal

Background: Pediatric vaccine clinical trials are crucial for evaluating and ensuring the safety and efficacy of new vaccines for children. However, in low-resource settings like Nepal, where clinical trials are relatively new, recruitment and retention of participants are challenging particularly due to diverse parental backgrounds, motivations and concerns. As such, parental motivations, perceived barriers, and experiences of participating in pediatric vaccine trial in Nepal, which hasn't previously been explored, needs to be understood.

Materials and methods: We performed face-to-face exit interviews from April 6, 2022 to June 7, 2022, with parents whose children participated in the phase III clinical trial of the Oral Cholera Vaccine - Simplified (OCV-S) using a structured questionnaire on motivations for enrolling and barriers faced during the trial. Data were initially cleaned and encoded in Microsoft Excel before being analyzed with R version 4.3.1. Descriptive statistics were used to summarize demographic and other participants' characteristics. Bivariate and multivariate analyses, using odds ratios and their 95% confidence intervals, applying a significance level of 0.05 was used to analyze relationship between participant characteristics and trial experiences. Additionally, thematic analysis was performed on responses to open-ended questions.

Results: A total of 258 parents responded, out of which 252 (97.7 %) were first-time clinical trial participants with median age of 32 years. A majority, 196 (76.0 %), had a positive initial attitude towards the trial, and 204 (79.1 %) reported a positive overall experience. The primary motivations for participation included the potential health benefits for their children (56.2 %, n = 145). Despite 69 (26.7 %) participants receiving discouraging information from others, only 4 (5.8 %) were influenced by it. Most participants (n = 219, 84.9 %), felt that the trial had met their expectations. Challenges faced included loss of time (n = 30, 11.6 %) and missed school for children (n = 22, 8.5 %). Nonetheless, 179 participants (69.4 %) expressed a willingness to enroll their children in future trials. Participants who received specific details about the study before visiting the study site were significantly more likely to report positive experience, with an adjusted odds ratio of 1.97 (95 % CI: 1.03 - 3.72).

Conclusion: Majority of parents were supportive of their children's participation in the OCV-S trial, motivated largely by anticipated health benefits for their child. Key barriers identified included logistical issues, costs (both financial and opportunity costs), misinformation, and concerns about trial procedures and potential side effects. Focus on reducing logistical and participation-related burdens, catering of trial-specific information, enhancing the clarity of the informed consent process, addressing safety concerns proactively and implementing continuous follow-up can help improve participation rates and retention in future trials. The high level of enthusiasm for clinical trials among parents, despite these barriers, highlights the promising potential for future research endeavors in Nepal.