The impact of cuts in the US President's Emergency Plan for AIDS Relief funding for HIV pre-exposure prophylaxis in sub-Saharan Africa: a modelling study.

backgroundIn January, 2025, the US Government issued a directive, pausing all foreign aid programmes. This directive included a 90-day pausing of all US President's Emergency Plan for AIDS Relief (PEPFAR) funding for HIV oral pre-exposure prophylaxis (PrEP) except for pregnant and breastfeeding women, with a return to funding for PrEP looking increasingly unlikely. We aimed to estimate the impact of a funding pause for PrEP on HIV infections in sub-Saharan Africa.

methodsIn this mathematical modelling study, we developed a static HIV transmission model incorporating PrEP, parameterised with estimates of population size, HIV prevalence and incidence, and PrEP effectiveness for different subpopulations (including key populations) in each PEPFAR-funded sub-Saharan African country. Key populations were men who have sex with men, female sex workers, transgender women, and people who inject drugs. We used PEPFAR reporting on numbers of people in different subpopulations returning for oral PrEP for each country in July to September, 2024, as the estimated number using oral PrEP provided by PEPFAR. For each country and subpopulation, we modelled the relative and absolute increase in new primary HIV infections resulting from removing this funded PrEP for a year and the number of secondary infections that could result from these primary infections during the next 5 years.

findingsTowards the end of 2024, 719 384 individuals who were not breastfeeding or pregnant, including 205 868 people from key populations, received PEPFAR-funded PrEP across 28 sub-Saharan African countries. The estimated proportion of HIV-negative key population individuals receiving PEPFAR-funded PrEP (ie, the coverage) ranged from 2·6% (95% uncertainty interval 2·0-3·4) in people who inject drugs to 5·0% (4·5-5·9) in female sex workers. Estimated coverage among non-key population men was less than 0·1% (<0·1 to <0·1) and in women was 0·1% (0·1 to 0·1). Stopping PEPFAR's provision of PrEP for a year could lead to 6671 (5032-8192) additional new primary HIV infections, including 5663 (4146-7074) in key populations. Within key populations, this absolute increase corresponds to relative increases in new HIV infections of 0·8% (0·3-1·5) in people who inject drugs, 1·4% (0·8-2·3) in transgender women, 2·2% (1·3-3·0) in men who have sex with men, and 2·9% (1·8-4·4) in female sex workers. In Zambia, the country with the highest PEPFAR coverage across all key populations, this increase ranges from 7·8% (2·5-17·1) in people who inject drugs to 18·1% (9·7-33·2) in men who have sex with men. When considering secondary transmissions, we estimated that a 1-year pause could lead to 10 313 (7796-12 921) additional infections during the next 5 years.

interpretationOur projections show the substantial detrimental impacts that cuts to PEPFAR funding could have. Mitigation measures, including funding through alternative international donors or domestic government budgets, are needed to maintain and increase existing coverage levels of PrEP and therefore prevent the detrimental impact of PEPFAR's funding cuts, particularly in high coverage countries.

fundingWellcome Trust. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.