Interview guide.

<div><p>Background</p><p>Vaccination during pregnancy is an important healthcare intervention for safeguarding the health of the mother and their infants. Ethnic disparities in recruitment to vaccine research studies during pregnancy potentially contribute to health inequalities. The aim of the current study was to explore the barriers and enablers influencing the willingness of pregnant women from ethnic minority backgrounds to participate in vaccine research studies.</p><p>Methods and findings</p><p>Semi-structured qualitative online interviews were conducted with 23 pregnant women from diverse ethnic backgrounds in the UK. Interviews were transcribed verbatim, and thematically analysed. Our findings suggest that participants perceived vaccines and vaccine research, in principle, to be beneficial to the individual and to society, and understood the value of vaccination in mitigating severity of disease and protecting the health of mothers and their infants. Apprehension over the safety of vaccination in pregnancy was common and reduced willingness to participate. For those that decided to participate in vaccine trials in pregnancy, this was seen as an act of solidarity, a way to contribute to a collective responsibility for the public health of the community. Personal and community connections and representation—seeing people from their own communities represented in in the recruitment process shapped decisions about vaccine trial participating. Trust and mistrust in health systems, shaped by past experiences of interacting with healthcare professionals were likely to inform whether they would consider participating. Practical considerations such as excessive time commitments related to study procedures, travel and organising childcare were barrier to participation. The level of invasiveness of trial procedures were also a concern, although increased monitoring during the trial was seen as a potential benefit, mitigating some safety concerns.</p><p>Conclusions</p><p>Our study reinforcing previously identified barriers to vaccine participation among pregnant women from diverse ethnic communities. This study underlines the need to develop tailored interventions that focus on fostering trust with the aid of community engagement to understand cultural contexts, establishing authentic representation, and address practical considerations, to contribute to enhancing vaccine trial participation in pregnancy in those from diverse ethnic communities.</p></div>