Authors

Sheena McCormack, Medical Research Council Clinical Trials Unit at UCL, London, UK
David Dunn, Medical Research Council Clinical Trials Unit at UCL, London, UK
Sylvia Kusemererwa, Medical Research Council/Uganda Virus Research Institute
Patricia Munseri, Muhimbili University Health and Allied Sciences, Dar es Salaam, Tanzania
Nishanta Singh, South African Medical Research Council, HIV and other Infectious Diseases Research Unit, Durban, South Africa
Wiston William, National Institute for Medical Research Mbeya Medical Research Centre
Gertrude Mutonyi, Medical Research Council/Uganda Virus Research Institute & London School of Hygiene & Tropical Medicine Uganda Unit, Uganda
Henry Bern, Medical Research Council Trials Unit at UCL, London, UK
Lauriane Goldwirt, Université de Paris Hôpital Saint-Louis Laboratoire de Pharmacologie Biologique
Cherry Kingsley, Imperial College of Science, Technology and Medicine, London, UK
Arne Kkroidl, LMU University Hospital
Christian Holm Hansen, Medical Research Council/Uganda Virus Research Institute & London School of Hygiene & Tropical Medicine Uganda Unit
Song Ding, EuroVacc Foundation
Rachel Kawuma, Medical Research Council/Uganda Virus Research Institute & London School of Hygiene & Tropical Medicine
Mary Amondi, International AIDS Vaccine Initiative
Ubaldo Bahemuka, Medical Research Council/Uganda Virus Research Institute & London School of Hygiene & Tropical Medicine Uganda Unit
Deus Buma, Muhimbili University Health and Allied Sciences
Daniel Clutterbuck, Medical Research Council Trials Unit at UCL
Zakir Gaffoor, South African Medical Research Council
Angus Jennings, Medical Research Council Clinical Trials Unit at UCL
Agricola Joachim, Muhimbili University Health and Allied Sciences, Dar es Salaam
Ayoub Kakande, Medical Research Council/Uganda Virus Research Institute & London School of Hygiene & Tropical Medicine Uganda Unit
Berna Kalanzi, Medical Research Council/Uganda Virus Research Institute & London School of Hygiene & Tropical Medicine Uganda Unit
Abisai Kisinda, National Institute for Medical Research Mbeya Medical Research Centre
Mabela Matsoso, EuroVacc Foundation
Thomas Miller, Imperial College of Science
Neetha MMedSci Morar, South African Medical Research Council
Jacqueline Musau, International AIDS Vaccine Initiative
Jane Nabbuto, Medical Research Council/Uganda Virus Research Institute & London School of Hygiene & Tropical Medicine
Ayanda Nzuza, South African Medical Research Council, HIV and other Infectious Diseases Research Unit, Durban, South Africa
Doreen Pamba, National Institute of Medical Research Mbeya Medical Research Centre
Simona Salomone, Medical Research Council Clinical Trials Unit at UCL, London, UK
Thandiwe Sithole, South African Medical Research Council, HIV and other Infectious Diseases Research Unit, Durban, South Africa
Edith Tarimo, Muhimbili University Health and Allied Sciences
Kubashni Woeber, South African Medical Research Council, HIV and other Infectious Diseases Research Unit
Kundai Chinyenze, International AIDS Vaccine Initiative
Glenda Gray, South African Medical Research Council
Eligius Lyamuya, Muhimbili University Health and Allied Sciences
Muhammad Bakari, Muhimbili University Health and Allied Sciences
Said Aboud, Muhimbili University Health and Allied Sciences
Lucas Maganga, National Institute for Medical Research Mbeya Medical Research Centre
Gustavo Doncel, Macon & Joan Brock Virginia Health Sciences at Old Dominion UniversityFollow
Janet Seeley, Medical Research Council/Uganda Virus Research Institute & London School of Hygiene & Tropical Medicine Uganda Unit
Jonathan Weber, Imperial College of Science
Pontiano Kaleebu, Medical Research Council/Uganda Virus Research Institute & London School of Hygiene & Tropical Medicine Uganda Unit
Julie Fox, Imperial College of Science
Eugene Ruzagira, Medical Research Council/Uganda Virus Research Institute & London School of Hygiene & Tropical Medicine Uganda Unit
on Behalf of the PREPVacc Study Group

ORCID

0009-0009-9641-1325 (Doncel)

Document Type

Article

Publication Date

2026

DOI

10.1097/qai.0000000000003845

Publication Title

Journal of Acquired Immune Deficiency Syndrome

Volume

Advance online publication

Pages

25 pp.

Abstract

Background:

F/TAF was shown to be non-inferior to F/TDF as pre-exposure prophylaxis (PrEP) in men, but approval was not extended to cisgender women. We report the results of PrEPVacc, in which a predominantly female population was randomly allocated to receive daily oral F/TDF or F/TAF for ∼6 months within a HIV-1 prophylactic vaccine trial.

Setting:

Five study sites in three African countries (Uganda, Tanzania, South Africa).

Methods:

The two regimens were compared by the averted infections ratio (AIR) - the proportion of infections averted by F/TAF relative to F/TDF. The counterfactual HIV incidence, an essential component of this metric, was derived from a preceding registration cohort. Dried blood spots (DBS) were collected at regular timepoints for later assessment of tenofovir diphosphate levels in selected sub-populations.

Results:

1380 participants (697 F/TDF, 683 F/TAF) were included in the primary analysis (total follow-up 709.2 person-years); 87% were cisgender women. Three HIV infections (0.86/100 person-years) occurred in the F/TAF group versus two in the F/TDF group (0.56/100 person-years). The counterfactual HIV incidence was estimated to be 2.59/100 person-years (90% CI 1.86-3.52), giving an AIR of 0.85 (90% CI 0.31-1.66). Based on the week 8 DBS sample , only an estimated 14% of participants were classified as taking 2-3 tablets per week and 9% ≥4 tablets per week.

Conclusions:

Despite similar HIV incidence rates, the non-inferiority of F/TAF was not demonstrated, probably due to low statistical power primarily driven by low adherence. However, there is compelling evidence from multiple studies supporting the efficacy of F/TAF as PrEP regardless of sex.

Rights

© 2026 The Authors

This is an open access article published under the Creative Commons Attribution 4.0 International (CC BY 4.0) License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Data Availability

Article states: "The policy of the PrEPVacc Steering Committee is to make de-identified participant data available to any researcher who submits a scientifically robust proposal, provided data exchange complies with information, governance, and data security policies in all the relevant countries."

Original Publication Citation

McCormack, S., Dunn, D., Kusemererwa, S., Munseri, P., Singh, N., William, W., Mutonyi, G., Bern, H., Goldwirt, L., Kingsley, C., Kroidl, A., Hansen, C. H., Ding, S., Kawuma, R., Amondi, M., Bahemuka, U., Buma, D., Clutterbuck, D., Gaffoor, Z.,…Ruzagira, E. (2026). A comparison of F/TAF and F/TDF as HIV pre-exposure prophylaxis in a predominantly cisgender women population in East and South Africa: A randomised, factorial, non-inferiority trial. Journal of Acquired Immune Deficiency Syndrome. Advance online publication. https://doi.org/10.1097/qai.0000000000003845

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