Factors, motivations and barriers associated with eagerness to volunteer in COVID-19 vaccine clinical trials in France: A mixed-method study

Abstract

IntroductionDuring the COVID-19 pandemic, there was an unprecedented effort to engage people in clinical vaccine research. Most of the French volunteers registered in the first weeks after the launch in October 2020 of COVIREIVAC, an electronic platform dedicated to COVID-19 vaccine clinical trials (VCT). In the context of pandemic preparedness, identifying factors associated with eagerness or hesitancy to participate in VCT may help to increase recruitment of volunteers from diverse backgrounds. MethodsWe used a mixed-method survey offered to the volunteers registered on the COVIREIVAC platform, and semi-directed interviews in participants to COVID-19 VCTs. Volunteers were divided into three categories: early volunteers (EV), registered before the launch of the COVID-19 vaccination campaign, middle volunteers (MV) registered between the first of January 2021 and the generalization of the COVID-19 vaccination to the entire population in May 2021, and late volunteers (LV) registered afterward. ResultsAmong the 56,101 COVIREIVAC registered volunteers, 2,741 (4.9 %) completed the survey, 1,915 (69.6%) were EV, 301 (11.0%) were MV and 525 (19.2 %) were LV. Sixteen were face-to-face interviewed. Age, educational level, attitudes toward vaccination evaluated with the 5C-model did not differ between EV and MV. Women gender and the possibility to choose the vaccine platform was associated with being a MV. LV were significantly younger, had a lower educational level and had less positive attitudes toward vaccines than EV and MV. The main motivations for participation in VCTs were altruistic notably in EV and MV. For LV, they registered in the hope to choice the vaccine technology. Among the respondents, 2,041 (74.5 %) would consider to participate in a non-COVID-19 VCT. ConclusionLV on the COVIREIVAC platform had a distinct profile from EV and MV, and were less confident in vaccines. Restoring confidence in vaccines and clinical may help to engage more diverse populations in VCTs.