Factors influencing engagement of at-risk individuals in cytomegalovirus vaccine clinical trials: insights from the USA

Abstract

Background To evaluate the willingness of US females of childbearing age, including high-risk groups, to participate in a CMV vaccine trial. Methods Two surveys, involving 238 and 680 females aged 18–49, assessed the impact of information sheets on willingness to participate in a CMV vaccine trial. The original survey studied the influence of information based on a CMV informed consent form. Following the finding that this Fact Sheet reduced willingness to enroll, an amended survey assessed the impact of different types of information on willingness to enroll. Results The first Fact Sheet decreased participation likelihood in both surveys (p = 0.055; p = 0.0139), while two more concise Fact Sheets significantly increased willingness to participate (p < 0.001 for both). Overall, 93% of respondents were generally aware of clinical research, but only 35% familiar with CMV. CMV awareness was highest in those currently or recently pregnant (overall, p < 0.001) and was moderately correlated to the willingness of enrollment in a CMV trial (rho = 0.3392, 2-sided p < 0.001). Greater percentages of participants who were initially marginally hesitant to enroll indicated they would be quite or very likely to participate after reading the concise Fact Sheets than those with greater baseline hesitancy. The willingness to participate in a CMV trial among Black/African Americans and those living with younger children did not increase after being informed of their specific higher risk from CMV. Conclusions Concise, relevant disease and risk information, informs willingness to enroll in CMV vaccine trials. However, dilution with information that does not resonate with readers may discourage those with the most to gain from clinical research participation.