RÉSUMÉ
Importance: The impact of COVID-19 in the US has been far-reaching and devastating, especially in Black populations. Vaccination is a critical part of controlling community spread, but vaccine acceptance has varied, with some research reporting that Black individuals in the US are less willing to be vaccinated than other racial/ethnic groups. Medical mistrust informed by experiences of racism may be associated with this lower willingness. Objective: To examine the association between race/ethnicity and rejection of COVID-19 vaccine trial participation and vaccine uptake and to investigate whether racial/ethnic group-based medical mistrust is a potential mediator of this association. Design, Setting, and Participants: This cross-sectional survey study was conducted from June to December 2020 using a convenience sample of 1835 adults aged 18 years or older residing in Michigan. Participants were recruited through community-based organizations and hospital-academic networks. Main Outcomes and Measures: Separate items assessed whether respondents, if asked, would agree to participate in a research study to test a COVID-19 vaccine or to receive a COVID-19 vaccine. Participants also completed the suspicion subscale of the Group-Based Medical Mistrust Scale. Results: Of the 1835 participants, 1455 (79%) were women, 361 (20%) men, and 19 (1%) other gender. The mean (SD) age was 49.4 (17.9) years, and 394 participants (21%) identified as Black individuals. Overall, 1376 participants (75%) reported low willingness to participate in vaccine trials, and 945 (52%) reported low willingness to be vaccinated. Black participants reported the highest medical mistrust scores (mean [SD], 2.35 [0.96]) compared with other racial/ethnic groups (mean [SD] for the total sample, 1.83 [0.91]). Analysis of path models revealed significantly greater vaccine trial and vaccine uptake rejection among Black participants (vaccine trial: B [SE], 0.51 [0.08]; vaccine uptake: B [SE], 0.51 [0.08]; both P < .001) compared with the overall mean rejection. The association was partially mediated by medical mistrust among Black participants (vaccine trial: B [SE], 0.04 [0.01]; P = .003; vaccine uptake: B [SE], 0.07 [0.02]; P < .001) and White participants (vaccine trial: B [SE], -0.06 [0.02]; P = .001; vaccine uptake: B [SE], -0.10 [0.02]; P < .001). Conclusions and Relevance: In this survey study of US adults, racial/ethnic group-based medical mistrust partially mediated the association between individuals identifying as Black and low rates of acceptance of COVID-19 vaccine trial participation and actual vaccination. The findings suggest that partnerships between health care and other sectors to build trust and promote vaccination may benefit from socially and culturally responsive strategies that acknowledge and address racial/ethnic health care disparities and historical and contemporary experiences of racism.