Understanding trial designs and acceptability of participation in an HIV vaccine trial with concurrent randomisation to oral pre-exposure prophylaxis in East and Southern Africa: a longitudinal qualitative study

INTRODUCTION: This qualitative study was conducted to assess participants' understanding of the PrEPVacc trial design and factors that influenced decisions to participate in the trial. PrEPVacc was a phase IIb, three-arm, two-stage HIV prophylactic vaccine trial with a second randomisation to oral pre-exposure prophylaxis. The main objective was to assess the safety and efficacy of two HIV-1 prophylactic vaccine regimens, each compared to placebo, in preventing the acquisition of HIV. METHODS: Using a longitudinal approach, qualitative data were collected between October 2021 and September 2023. A sample of 105 participants (7% of trial participants) was purposively selected to participate in three in-depth interviews at 2, 6, and 12 months during the trial. Another 111 (92 females and 19 males) participated in 14 focus group discussions across four sites. Data were analyzed thematically. RESULTS: Repeated information sharing sessions facilitated by health workers helped participants understand key trial concepts and the design. Pre-exposure prophylaxis (PrEP) was widely recognised as a protective measure alongside experimental vaccines. While vaccines were preferred for convenience and minimal side effects, individual perceived HIV risk was a main motivation for adhering to PrEP. Supportive relationships with health workers and close family members encouraged engagement in the trial, including acceptance to use the products. However, misinformation and stigma in communities created barriers to participation, with some participants facing social harm. CONCLUSION: Overall, participants demonstrated a good understanding of randomisation, double-blinding, and placebo control, facilitated by clear, repeated communication from health workers. Strengthening strategies to enhance informed consent, reduce stigma, and promote trial acceptance is crucial for successful implementation and retention. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT04066881. Registered on December 15, 2020.

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Journal
Trials
Published
2026-05-16
DOI
https://doi.org/10.1186/s13063-026-09774-5
Primary Topic
Ethics in Clinical Research
Type
article
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article

Understanding trial designs and acceptability of participation in an HIV vaccine trial with concurrent randomisation to oral pre-exposure prophylaxis in East and Southern Africa: a longitudinal qualitative study

Eldinah Hwengwere, Deus Buma, Sylvia Masawi, Amani Kway et al.
Trials
Ethics in Clinical Research
article

Understanding trial designs and acceptability of participation in an HIV vaccine trial with concurrent randomisation to oral pre-exposure prophylaxis in East and Southern Africa: a longitudinal qualitative study

Eldinah Hwengwere, Deus Buma, Sylvia Masawi, Amani Kway, Edna Nhacule, Jennifer Serwanga, Diana Faini, Aminata Sy, Mabela Matsoso, Sarah Nakamanya, Jacqueline Musau, Kundai Chinyenze, Emmanuel Kapesa, Sarah Joseph, Rachel Kawuma, Nteboheleng Mahapa, Yolanda Manganhe, Henry Bern, Odete Bule, Rujeko Samanthia Chimukuche, Vincent Basajja, Eduardo Namalango, Nishanta Singh, Zakir Gaffoor, Liz Brodnicki, Anne Gumbe, Frank Msafiri, Eugene Ruzagira, Silindile Zulu, Said Aboud, Lilian Njovu, Paramesh Chetty, Isabel Remane, Wiston William, Esther Awino, Claire Wenden, Kubashni Woeber, Sylvia Kusemererwa, Shamim Nabukenya, Georgina Nabaggala, Merlin Robb, Ayoub Kakande, Rujeko Samanthia Chidawanyika, Carter Lee, Revocatus Kunambi, Sheila Kansiime, Gertrude Mutonyi, Elizabeth Danstan, Christian Hansen Holmes, Jane Ambindwile, Londiwe Shandu, Simona Salomone, Tom Miller, Muhammad Bakari, GF Doncel, Ansuya Naidoo, Marco Missanga, Thandiwe Sithole, Edith Tarimo, Arne Kroidl, Cherry Kingsley, Masunga Iseselo, Samantha Siva, Doreen Pamba, Lwitiho Sudi, Lucas Maganga, Pontiano Kaleebu, Agricola Joachim, Freddie Mukasa Kibengo, the BRAVO-CAD study team, Ilesh Jani, Phindile Khanyile, Julie Fox, Tumaini Nagu, Jim Rooney, Charlotta Nilsson, Gift Gadiel, Eligius Lyamuya, Song Ding, Neetha Morar, Patricia Ramgi, Sheena McCormack, Jorge Ribeiro, Jonathan Weber, Angela Crook, David Dunn, Patricia Munseri, Raquel Chissumba, Joel Ambikile Seme, Mary Amondi, Allison Matthews, Edna Viegas, Carmelia Massingue, Igor Capitine, Glenda Gray, Janet Seeley, Abisai Kisinda, Tausi Sade, Karine Dubé, Giuseppe Pantaleo
article en

Abstract

INTRODUCTION: This qualitative study was conducted to assess participants' understanding of the PrEPVacc trial design and factors that influenced decisions to participate in the trial. PrEPVacc was a phase IIb, three-arm, two-stage HIV prophylactic vaccine trial with a second randomisation to oral pre-exposure prophylaxis. The main objective was to assess the safety and efficacy of two HIV-1 prophylactic vaccine regimens, each compared to placebo, in preventing the acquisition of HIV. METHODS: Using a longitudinal approach, qualitative data were collected between October 2021 and September 2023. A sample of 105 participants (7% of trial participants) was purposively selected to participate in three in-depth interviews at 2, 6, and 12 months during the trial. Another 111 (92 females and 19 males) participated in 14 focus group discussions across four sites. Data were analyzed thematically. RESULTS: Repeated information sharing sessions facilitated by health workers helped participants understand key trial concepts and the design. Pre-exposure prophylaxis (PrEP) was widely recognised as a protective measure alongside experimental vaccines. While vaccines were preferred for convenience and minimal side effects, individual perceived HIV risk was a main motivation for adhering to PrEP. Supportive relationships with health workers and close family members encouraged engagement in the trial, including acceptance to use the products. However, misinformation and stigma in communities created barriers to participation, with some participants facing social harm. CONCLUSION: Overall, participants demonstrated a good understanding of randomisation, double-blinding, and placebo control, facilitated by clear, repeated communication from health workers. Strengthening strategies to enhance informed consent, reduce stigma, and promote trial acceptance is crucial for successful implementation and retention. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT04066881. Registered on December 15, 2020.

Trials
South African Medical Research Council (ZA), Muhimbili University of Health and Allied Sciences (TZ), London School of Hygiene & Tropical Medicine (GB), MRC Clinical Trials Unit at UCL (GB), Africa Health Research Institute (ZA), National Institute for Medical Research (TZ), University College London (GB), University of Pennsylvania (US), Uganda Virus Research Institute (UG)
Gilead Sciences, Medical Research Council, European and Developing Countries Clinical Trials Partnership
Good health and well-being
Openalex Percentile: Top 5%
Ethics in Clinical Research
DOIOpen Access PDFOpenAlex
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