Experiences of participant engagement from an African and Asian ancestry cohort during a clinical research study of lymph node responses to influenza immunisation in the United Kingdom

Experiences of participant engagement from an African and Asian ancestry cohort during a clinical research study of lymph node responses to influenza immunisation in the United Kingdom | Research Square Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Experiences of participant engagement from an African and Asian ancestry cohort during a clinical research study of lymph node responses to influenza immunisation in the United Kingdom Daisy Metcalf, Natalie ST Man, Sofia Coelho, Aime Palomeras, Seung Joon Kim, and 9 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8079872/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Despite the importance of diversity and inclusion for equity in health outcomes, ancestral diversity is underrepresented in clinical studies of human immunity and immunisation. The global population is incompletely represented in vaccine trials and in publicly available datasets of human tissue such as the Human Cell Atlas. LEGACY01 (ISRCTN13657999) was an experimental medicine study at NIHR Imperial Clinical Research Facility, London, UK, which focused on addressing this inequity by investigating influenza vaccine responses in the lymph nodes of an ethnically diverse cohort. Methods The study included participants with self-declared African or Asian ancestry. Participants in the second season cohort (2023–2024), were surveyed on their experiences during the study. Participants underwent fine needle aspiration (FNA) of axillary lymph nodes before and 5 (+/-2) days post vaccination with a seasonal influenza vaccine. Participants were asked about symptoms, called adverse events (AEs), related to FNA and whether they wanted to take part in a research experience questionnaire to assess overall satisfaction, willingness of participation and areas for improvement. Results Participants enrolled (n = 17) during the influenza season of 2023–2024 were from eight self-declared ethnicities. Adverse events related to FNA, including pain and bruising at the procedure site, were reported by 13/17 (76.5%) participants, but these were generally expected, transient and well-tolerated symptoms that did not negatively affect completion of the study or willingness for further procedures. In the survey, participants recorded that factors such as the friendliness of study staff and ease of process contributed to their positive research experience. 17/17 (100%) participants agreed or strongly agreed that they felt informed and comfortable with asking questions, believed staff treated them with respect and courtesy and were overall satisfied with the services provided. Using a Likert scale, 15/17 (88.2%) participants agreed or strongly agreed that they would consider participating in future studies. Conclusions The research conducted in LEGACY01, which included a minor biopsy procedure, met with an overwhelmingly positive response. Research participation by underserved communities can be successful through efforts to facilitate communication and comfort during the research experience and by highlighting the importance of diversity in research to potential participants. Trial registration number: ISRCTN13657999 Registration date: 09/09/2022 ethnic minority groups diversity inclusion research experience ancestry Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Background Representation of diversity across ethnicities in clinical research of human immunity and immunisation has historically been challenging due to a range of complex factors, such as mistrust of healthcare professionals and lack of representation amongst researchers 1 . At the same time, global efforts to characterise human tissue at the single cell level in publicly available reference datasets such as the Human Cell Atlas, has been hampered by a limited range of possible donors 2 . The National Institute for Health Research (NIHR), UK, has identified “under-served” groups in clinical research, which include those from low socioeconomic backgrounds, from UK ethnic minority groups, or with impaired capacity to consent 3 . The LEGACY01 (Lymph nodE single cell Genomics AnCestrY Network) study was designed to investigate lymph node cell function in response to influenza vaccine in UK residents from diverse ancestral backgrounds. Throughout the study, local community involvement was fostered through both participant recruitment drives and via wider patient and public involvement and engagement (PPIE) events. The objective was to develop a publicly available reference dataset to better understand the role of ancestry in the immune response, with the aim of enabling the design of better vaccines and therapeutics that protect health and prevent disease. Socio-economic deprivation, cultural and religious beliefs, systemic and language barriers all contribute to lower engagement in research studies, and many studies do not consistently report data on inclusion 4 – 6 . This lack of diversity is a growing concern, as research findings are not fully representative of all ethnic groups, ultimately reinforcing healthcare inequalities 7 . When amplified to the global scale, this inequity in research engagement risks our collective resilience to new and emerging infections and limits our ability to design safe and effective vaccines. The COVID-19 pandemic highlighted the disparities in patient outcomes across different ethnicities. Evidence from the UK showed that individuals from Black or Asian backgrounds faced higher rates of hospitalisation and mortality due to COVID-19 compared with White British adults but vaccine hesitancy was also greater 8 – 9 . The problem is not confined to COVID-19 vaccination, with seasonal influenza vaccine uptake being substantially lower in Hispanic, Black and Asian older adults receiving Medicare in the US compared with White adults 10 . The World Health Organisation recognised this as one of the top ten threats to global health in 2019 as low vaccine uptake leads to higher burden of disease 11 . Understanding human immunity, particularly lymph node function is important for the design of new vaccines against infectious disease and for the development of cancer vaccines. With the advent of new tools including generative artificial intelligence, protein folding and receptor binding prediction, this progress will be increasingly dependent on detailed characterisation of the human immune system at the cellular and molecular level. Efforts to achieve this with studies that yield publicly available datasets are already underway, however these are limited by a narrow spectrum of tissue donors who are mostly White European in ancestral origin; for example the Human Lung Cell Atlas contains data from individuals identifying as European (65%) with only 14% African and 2% Asian 12 . The human leukocyte antigen (HLA) which encodes major immune receptors, is an important target for new drug and vaccine development, and is one of the most ancestrally diverse regions of the human genome. Most donors are HLA-A02 restricted and public datasets lack data on a broad range of other HLA-types 13 . A review of registered clinical trials of therapeutics that restricted enrolment based on HLA typing demonstrated that HLA-A2 or HLA-A*02:01 were the most common specifications. Prevalence of HLA-A subtypes varied significantly between ethnicities and thus reduced the likelihood of enrolment of different ethnicities, with only 7.7% of non-White participants enrolled in one subset of HLA-based therapy clinical trials 14 . Within the human immune system, lymph nodes are the specialised organs which co-ordinate the immune response including the functions of HLA-restricted immune cells; in the context of immunisation, these organs are critically important in forming new cells and antibodies in response to the vaccine. Previously, our ability to study their function in response to immunisation was limited by problems with direct access, as they are relatively small (typically < 1cm) and scattered throughout the body in chains that follow veins and arteries 15 . Developments in ultrasound imaging have changed this. Modern brightness (B)-mode ultrasound can directly image lymph nodes in real time, allowing them to be sampled with a needle, using a procedure termed fine needle aspiration (FNA). Studies of lymph node function in the context of immunisation have been published but have not directly addressed the question of ethnic diversity. The data arising remain limited by the same narrow representation of global ancestral diversity, consistent with previous vaccination studies of the blood. Here we report participant experience data from the LEGACY01 study to explore the possible factors that might influence uptake of research participation and lymph node tissue donation within ethnic minority groups, where diversity is critical to the data value. Methods Description of the clinical research study LEGACY01 was a non-randomised, open label, experimental medicine study, approved by the London - Central Research Ethics Committee and registered, ISRCTN13657999. The study was conducted at the NIHR Imperial Clinical Research Facility (CRF), West London, UK. A detailed description of the scientific study and the protocol is available 16 , 17 . Healthy volunteers aged 18 to 55 years with self-declared African or Asian ancestry were enrolled, with the second cohort during the 2023–2024 winter season. Participants declared their ethnicity from the ethnicity groups listed by the Office for National Statistics in England and Wales 18 . Informed consent was obtained from all participants prior to enrolment. Participants received an adjuvanted seasonal influenza vaccine (aQIV), and lymph node cells from axillary lymph nodes were sampled by ultrasound guided FNA prior to 5(+/-2) days after vaccination, and optionally at 6 weeks. Peripheral blood samples were taken alongside FNA sampling, and additionally at 28 days post-vaccination. In recognition of the time and travel expenses incurred from involvement in the study, participants were compensated via Bankers’ Automated Clearing System payment at the end of study as per Health Research Authority payments and incentive guidance and approval from the Research Ethics Committee. Adverse event recording Adverse events (AEs) reported by participants during participation in the study were recorded in the first 5 days following FNA for the purpose of assessing the participant’s experience of the biopsy procedure. AEs following immunisation were recorded if they occurred during the 28 days following vaccination. These data were collected to ensure the safe and ethical conduct of the study. Any unexpected symptoms after immunisation would have been reported to the regulator in the UK medicines reporting system in accordance with its license. These data were stored electronically on a bespoke study database, Research Electronic Data Capture (REDCap). Description of the participant survey Participant experience was assessed through an optional and confidential paper survey provided at the end of study (supplemental data) and the results were entered and stored on the REDCap database. The survey was designed by the study team and comprised of 13 questions. Each question assessed the following domains: visit completion status, previous research experience, demographics, study experience, lymph node sampling experience, motivations for participation, satisfaction with financial compensation, early withdrawal consideration, study discovery methods, positive feedback and ideas for improvement. The study experience question was further divided into three categories – experience prior to the start of study, during and post study participation, and responses were collected via a Likert scale. Questions on pre-study participation assessed whether the participant information sheet prepared participants for the study, whether site staff provided clear information and whether participants felt comfortable with asking questions. Participants were also asked whether site staff were respectful and courteous, whether they felt encouraged and supported during the visit, if they were confident in contacting study staff and if study visits were well-planned. Participants were then asked to rate the overall experience of the site services and if they would consider participating in research again. The axillary lymph node FNA experience was explored in terms of whether participants were satisfied with explanation of the procedure, felt at ease during the procedure and if they experienced pain using dichotomous questions. Intensity of pain was also measured as either very mild, mild, moderate or severe. Participants were also asked if they would participate in an additional visit if offered. A free textbox was provided for additional comments on the procedure. Study motivation was explored as a multiple-choice question with the following possible answers: to contribute to research and help others, positive experience in another clinical study, to contribute to diversity and inclusion in research and financial compensation. A free textbox was provided for other reasons. Participants were asked if they had considered early withdrawal from the study and whether the following influenced their decision: frequent or lengthy visits, dislike of lymph node procedure, side effects of the vaccine, duration of study, travel time, limited staff support, COVID-19 or ‘other’ as an option in free text. The last two questions required free text responses in terms of what was positive about their study experience and what could have improved their experience. Free text responses were analysed to identify key terms describing the positive aspects of participant research experience and suggestions on how to improve the study experience. Text data was processed and visualised as a word cloud analysis using the Python word cloud library (v3.13.1) and displayed with Matplotlib (v3.10.0). Size of the key terms were displayed proportional to the frequency of the term. Public and participant involvement and engagement (PPIE) Feedback from expert participants Two patient and public representatives from the Asian and Black communities who sat on the NIHR Imperial CRF PPIE panel and had expertise in public involvement in clinical research were appointed as PPIE champions for this study. They sat on the protocol development team and reviewed the study design and patient facing materials prior to regulatory submission, to ensure clarity and understanding. They also attended the protocol development fortnightly meetings for study updates and progress. These PPIE champions were trained and supported by the PPIE manager and Principal Investigator about the study and commitments of the role so they could contribute effectively. The whole study team were actively involved in community events (Great Exhibition Road Festival and Lambeth Country Show Festival) and engaged with the local communities about the importance of vaccination and the stigma around clinical trials from their perspective 19 . Involvement and engagement To recruit our target population, we sought advice from the Imperial College Healthcare NHS Trust Multidisciplinary Race Equality Network in how to effectively approach and engage with communities from ethnic minority backgrounds. For example, the design of the advertising materials focused on appealing to the local community. Community outreach was fostered with support from the British Society for Immunology by hosting vaccine engagement events such as the Imperial Great Exhibition Road Festival and Lambeth County Fair, designed to engage people from diverse communities that are representative of London, UK 19 . Similarly, recruitment was focused on the local student and healthcare staff population via events such as the Imperial Welcome Fair and promoting the study via the School of Medicine Student Union’s newsletters and the NHS Staff bulletin boards. LEGACY01 was also advertised on the Imperial CRF social media pages and other external social media pages to broaden the search and reach out to more communities. Statistical analysis Statistical analysis was performed using SPSS and significance level was determined as p < .05. Here we report data from participants in the second seasonal cohort (Cohort 2), who completed all study visits in 2023–2024 (n = 17). Results 17 adult volunteers with self-declared African or Asian ancestry were enrolled onto the second study cohort during the influenza season of 2023–2024. Two additional participants were enrolled but withdrew before completing all study visits and the research experience survey (Fig. 1 ); of the 17 participants, 14 identified as female (82.4%), two as male (11.8%), and one participant selected 'prefer not to say’ (5.9%) (Table 1 ). The median age of participants was 25 years (IQR 23–32). Participants identified themselves as belonging to Chinese, Indian, Pakistani, Bangladeshi, Afghan, Arab, Caribbean and African ethnicities (Table 1 ). The most frequently recorded ethnicity was Indian, 4/17 (23.5%). Table 1 Self-reported demographic data from the participant research experience survey. Characteristic n (%) Sex Female 14 (82.4) Male 2 (11.8) Prefer not to say 1 (5.9) Age Median 25 IQR 23–32 Self-reported ethnicity Indian 4 (23.5) Bangladeshi 3 (17.6) African 3 (17.6) Arab 2 (11.8) Chinese 2 (11.8) Caribbean 1 (5.9) Pakistani 1 (5.9) Other (Afghan) 1 (5.9) Events reported by participants after the lymph node fine needle aspiration procedure The experience of the FNA procedure was assessed quantitatively by means of AE recording during the study and qualitatively by means of a participant survey at the participant’s completion of the study visits (Table 2 ). Half of the AEs, 48/93 (51.6%) reported were associated with the FNA procedure. Amongst the participants, 13/17 (76.5%) experienced at least one AE related to FNA and four participants reported no AEs related to FNA. AEs related to FNA were classified according to the Food and Drug Administration (FDA): Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials 20 . Most were Grade 1 (mild) symptoms, (47/48, 97.9%), with only one instance recorded as Grade 2 (moderate). Three main types of AEs were observed following FNA; pain or tenderness, bruising and numbness. Pain or tenderness was the most common AE, reported in 31 out of 48 cases (64.6%), followed by bruising (16/48, 33.3%) and numbness (1/48, 2.1%). Notably, the terms "pain" and "tenderness" were used interchangeably in the data collection. Table 2 Adverse events (AEs) following the lymph node fine needle aspiration (FNA) procedure. n (%) Fine needle aspiration procedure related adverse events 48 Severity Mild/Grade 1 47 (97.9) Moderate/Grade 2 1 (2.1) Types of AEs Pain/Tenderness 31 (64.6) Bruising 16 (33.3) Numbness 1 (2.1) Timing of AE onset post-FNA Within 12 hours 42 (87.5) Within 24 hours 46 (95.8) Within 48 hours 48 (100) Mean duration of FNA-related AEs 3.7 days (± 3.5 days) Mean duration by AE type Pain/Tenderness 2.4 days (± 1.8 days) Bruising 6.3 days (± 4.4 days) There was no statistically significant association between the anatomical site of the FNA (left vs. right axilla) and the occurrence of AEs, χ² (1, n = 47) = 0.51, p = .477. Most FNA-related AEs (42/48, 87.5%) were reported within the first 12 hours post-procedure. By 24 hours, 46 out of 48 (95.8%) AEs had occurred, and all AEs (100%) were observed within 48 hours of the FNA procedure. The mean duration of AEs related to FNA was 3.7 days (± 3.5 days). Bruising had a longer average duration of 6.3 days (± 4.4 days), whereas pain resolved more quickly, with an average duration of 2.4 days (± 1.8 days) (Table 2 ). Result of the participant survey; study engagement and FNA procedure All 17 participants completed the research experience survey at the end of study. 10/17 (58.8%) reported that this was their first time participating in research. 12/17 (70.6%) heard about LEGACY01 from Imperial College London communications, 3/17 (17.6%) from the Imperial College Healthcare NHS Trust communications, 2/17 (11.8%) from the local community, 1/17 (5.9%) from a family member/friend and 1/17 (5.9%) via internet search. All 17/17 (100%) participants reported that they were satisfied with the explanation of the FNA procedure and felt at ease during the procedure (Fig. 2 ). In line with the findings in the quantitative survey, 11/17 (64.7%) reported pain during the procedure. 8/17 (47.1%) experienced very mild or mild pain, 1/17 (5.9%) reported mild/moderate pain, 2/17 (11.8%) reported moderate pain and none experienced severe pain during the procedure. 13/17 (76.5%) participants were interested in taking part in an optional additional third FNA study visit to assess longer term lymph node responses to the seasonal influenza vaccine. Participants were presented with multiple options for motivation to participate in research. 14/17 (82.4%) agreed that contributing to equality, diversity and inclusion was a factor for participation. 12/17 (70.6%) selected contributing to research and helping others. 10/17 (58.8%) of participants selected financial compensation as a reason. 17/17 (100%) participants felt compensation was reasonable and only 3/17 (17.6%) considered early withdrawal from the study. Of these, two reported timing of the visits as the reason, one reported travel time and the study procedure and one did not give a reason. Result of the participant survey; study satisfaction, suggestions for improvement and overall experience A 5-point Likert scale (strongly disagree, disagree, neither agree nor disagree, agree, strongly agree) was used to describe different aspects of the study experience. None of the participants disagreed or strongly disagreed with the statements (Fig. 3 ). 14/17 (82.4%) of participants strongly agreed that the participant information sheet (PIS) prepared them for the study and the remaining 3/17 (17.6%) agreed. 16/17 (94.1%) strongly agreed that the information provided by the study team was clear and easy to understand. The same number felt comfortable asking questions and knew whom to contact. Similarly, 16/17 (94.1%) of participants strongly agreed that staff were courteous and respectful and 15/17 (88.2%) strongly agreed that they felt encouraged and supported. 15/17 (88.2%) strongly agreed that visits were well planned and organised. The overall satisfaction level with site services was high, with 16/17 (94.1%) selecting ‘strongly agree’. Finally, 14/17 (82.4%) of participants strongly agreed that they would consider taking part in research again, one agreed and 2/17 (11.8%) participants did not agree or disagree with this statement. Suggestions from participants on how to improve their experience of the study included greater flexibility of visit timings and shorter visits (Fig. 4 ). Participants used several different terms to describe what they found positive about their research experience (Fig. 5 ). Participants reported that they felt the experience was ”friendly” and ”clear” and found the staff “nice” and ”supportive”. Other key words that were mentioned included “flexible” visits and offers of refreshments and biscuits, during their visits. Discussion Participants from diverse African and Asian ethnicities reported a positive research experience in this UK based study, with a sense of being well-informed and supported by the study team as prominent themes. The FNA procedure was well tolerated, with related events, mainly pain and bruising at the procedure site, being mild and transient. Notably, participants expressed an interest in future research studies, despite over half of participants having no previous experience in clinical research. The ancestral diversity of this research is important because of the profound underlying immunological variation, for example in HLA alleles across populations, which has direct implications for the development and accessibility of immune-targeted research reagents, drugs and vaccines. HLA alleles are unequally distributed amongst different ancestral backgrounds, yet most HLA-based research reagents, therapies and vaccines, particularly in oncology, target those most prevalent in people of European descent 21 . By taking an inclusive approach, this study demonstrated that this inequity can be addressed amongst an ancestrally diverse cohort. Although clinical research reflects a controlled microcosm of general healthcare, the barriers to access for ethnic minority groups remain consistent across both healthcare and research. These well-established factors include mistrust of healthcare professionals, socioeconomic status, health literacy and awareness, and language and cultural barriers 5 . Crucially, the lack of ethnic diversity within clinical research acts a barrier to participation in itself. Key facilitators to recruitment in under-served groups include early community engagement, culturally relevant materials and personalised approaches. Specifically, community-based participatory research approaches have proven effective in improving recruitment and retainment, as members of the community are actively engaged as partners in research and involved in all aspects from study development to dissemination of findings 22 . Local events and recruitment drives were planned around engaging the local community and the PPIE champions provided a valuable contribution to the design and setup of the study. Our findings show that the main motivations for taking part were contributing to diversity and inclusion within research and contributing to research and helping others generally. Contributing to science and helping others have been cited as reasons for participating in research 23 . Financial reimbursement for time spent at the study site and contributing to the research was also a motivation for participation. The payment schedule was set to be proportionate to the time and personal burden of taking part, and received ethical approval as part of the study review by the Research Ethics Committee. The importance of financial compensation in recruitment of participants may vary depending on the cohort studied, and other motivators, such as contributing to knowledge about disease, have higher importance in patient groups 24 – 26 . Consistent with our findings, financial compensation may not be a key incentive to recruitment, with altruistic factors such as contributing to research diversity holding more importance. Research staff play a pivotal role in shaping the experience of participants. The participants in our study noted the friendliness and professionalism of the research staff. Previous research has shown that people from ethnic minority groups may be more susceptible to lower quality interactions with research staff with negative experiences reducing future enrolment 27 . The opposite was evident in this study. In future, it would be of value to explore how the demographics of staff could impact participant-staff interactions and recruitment in this population. Understanding the post-procedure symptom profile within a diverse cohort could inform strategies to improve future recruitment into clinical research requiring tissue biopsy. Pain during the procedure was managed using local anaesthetic, which has a short duration of action. We found that pain and bruising were the most reported after-events associated with FNA, consistent with expectations outlined in the study participant information sheet. In addition to recording AE frequency, the participant survey characterised the severity of pain following FNA, revealing the majority reporting it as mild, and indicating a willingness to undergo an optional repeat procedure. The frequency and nature of post procedure symptoms have not been previously highlighted as barriers to research participation in underrepresented ethnicities, however it is important to consider that pain perception and expression are influenced by cultural factors. Such differences underscore the importance of culturally sensitive assessment and communication about adverse effects to support inclusive research participation. Limitations A limitation of the study is that the recruitment strategy meant that most participants recruited were individuals working or studying in a medical or science field. Consequently, the data possibly reflects those with a high educational attainment. Although the study concentrated on the under-served ethnic minority groups, it is important for future research to further diversify the educational and socioeconomic backgrounds of participants, both within these groups and beyond. Conclusions Our study highlights the feasibility and acceptability of involving ethnically diverse participants in a vaccine immunology study that included tissue biopsy, demonstrating positive experiences, high tolerance of procedures, and strong altruistic motivations to contribute to diversity in science. Importantly, diversity was built into the research question, choice of study population, and our methodology to engage and conduct research with those populations. Surveying participant research views demonstrated that the time and effort spent on recruitment to research delivery was effective – most participants were happy to take part in research in the future again and felt satisfied with the study process. Moving forward, this work acts as an exemplar of the possibilities for researchers to work with local communities in the recruitment of ethnic minorities to increase equality, diversity and inclusion within research that requires potentially sensitive procedures such as tissue donation. Abbreviations AEs adverse events aQIV adjuvanted quadrivalent influenza vaccine fine needle aspiration (FNA) CRF Clinical Research Facility FDA Food and Drug Administration HLA human leukocyte antigen LEGACY01 Lymph nodE single cell Genomics AnCestrY Network NIHR National Institute for Health Research PPIE patient and public involvement and engagement REDCap Research Electronic Data Capture Declarations Ethics approval and consent to participate This study was approved by the London - Central Research Ethics Committee (REC ref: 22/LO/0343). and the participants provided written informed consent to participate prior to enrolment. Consent for publication Not applicable, no individual data are included. Availability of data and materials The data supporting the conclusions of this article are included within the article and its additional files. Competing interests KMP has received research funding support from Horizon 2020, the NIHR, and The Sir Joseph Hotung Charitable Settlement outside the submitted work. KMP has received honoraria from CSL Seqirus for speaking, travel support from CZI and has participated in Moderna data safety monitoring boards. KMP has a role on the British HIV Association immunisation guidelines writing committee, the UK Clinical Vaccine Network and was on the UK NIHR COVID-19 Chief Investigators group. All other authors declare no competing interests. Funding This study was funded by the Silicon Valley Community Foundation with a donation from the Chan Zuckerberg Initiative for the Ancestry Network initiative (grant 2021-239944 (5022)). The funder had no role in the study design, data collection, analysis, decision to publish, or preparation of the manuscript. Authors' contributions DM: acquisition, analysis, data interpretation, drafting and revising the manuscript; NM: acquisition, analysis, data interpretation, drafting and revising the manuscript; SC: design, acquisition, analysis; AP: design, acquisition, analysis; SJK: analysis; BDM: acquisition, TS: acquisition; JHS; acquisition, data interpretation, MC; design, acquisition, CAD; design, acquisition, data interpretation;  DBP: design, data interpretation, revising the manuscript; SV: design, data interpretation, drafting and revising the manuscript; KMP: conception, design, acquisition, analysis, data interpretation, drafting and revising the manuscript. All authors approved the submitted version and have agreed both to be personally accountable for the author's own contributions and to ensure that questions related to the accuracy or integrity of any part of the work, even ones in which the author was not personally involved, are appropriately investigated, resolved, and the resolution documented in the literature. Acknowledgements We would like to acknowledge the Imperial College London, University of Oxford and Uganda Virus Research Initiative LEGACY Network investigators for their support in this study. We would like to thank the LEGACY Network PPIE representatives for their feedback and support. JHY is supported by Wellcome funding (I226938/Z/23/Z). KMP holds an MRC Clinician Scientist Fellowship (MR/W024977/1). References Flores LE, Frontera WR, Andrasik MP, del Rio C, Mondríguez-González A, Price SA, et al. Assessment of the inclusion of racial/ethnic minority, female, and older individuals in vaccine clinical trials. 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Supplementary Files TrialsNov25STROBEchecklistcohort.docx ISRCTN13657999PROTOCOLV3.106Jul23.pdf TrialsNov25AdditionalFile1Appendix1.pdf Supplemental file 1: Appendix 1: LEGACY01 Participant Survey. Participant research experience survey completed by participants in cohort 2 of LEGACY01 study (pdf) Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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