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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