Scaling back PEPFAR will leave 700,000 without PrEP and cause 6700 new HIV infections within a year

The 13th International AIDS Society Conference on HIV Science (IAS 2025) in Kigali, Rwanda has been dominated by the impact of the US government funding cuts. Especially urgent are discussions on how to finance prevention programmes now that PrEP, for any reason other than to prevent vertical HIV transmission, will no longer be supported by PEPFAR, the President’s Emergency Plan for AIDS Relief, which was responsible for supporting 90% of PrEP provision in low and lower-middle income countries till January this year.

A modelling study by Dr Jack Stone of the University of Bristol estimated that if none of the withdrawn PEPFAR funding is replaced in 28 countries in sub-Saharan Africa, over 700,000 people would lose access to PrEP. This will add between 6700 and 16,000 new cases of HIV within one year.

It is notable, however, that the lower estimate only represents an increase of 2.1% in annual infections in the 28 countries. The reason the sudden loss of PrEP will not immediately lead to a greater rise in HIV incidence is mainly because even in 2024 the proportion of people using PrEP was still not enough to prevent more than a small proportion of new infections in these countries, many of which have very high HIV incidence, especially in young people.

Even before the US cuts, in short, PrEP was not being used to anything like the extent that would lead to a really significant fall in HIV incidence.

The model used PEPFAR’s own figures for coverage, disaggregated where possible into coverage for so-called key affected populations at high risk of HIV. These are female sex workers (FSW), gay and bisexual men who have sex with men (MSM), transgender women (TGW), and people who inject drugs (PWID). It also considered cisgender men and women who are not members of a key population.

It estimated how many new HIV infections would fail to be prevented by the lack of PrEP by averaging efficacies seen in research studies. These averages are inevitably lower than the ideal efficacy achieved in randomised studies, especially of injectable PrEP. Efficacies used as inputs into the model were 75% efficacy in MSM and TGW (so using PrEP would stop three out of four possible infections), 69% in heterosexual men, 49% in PWID, 39% in FSW and only 31% in cisgender women. If higher efficacy estimates were used, this would increase the number of additional HIV infections caused by PrEP being withdrawn.

The study found that a total of 742,000 people in the 28 African countries were on PrEP funded by PEPFAR last year. Of these, 23,000 (3.1%) would still receive PrEP because they were pregnant or breastfeeding women, so 719,000 (96.9%) have lost PEPFAR-supported PrEP.

Of the 742,000, 28% were members of key populations: 18.4% were FSW, 7.1% MSM, 1.7% PWID and 0.5% TGW. Of the remaining 69% who were not in a key population or the mothers of babies, 47% were women and 23% men.

PrEP, even supported by PEPFAR, was still, up until last year, only reaching a small proportion of those who might benefit from it. Even for FSW, the group with the highest coverage, it was estimated that PrEP was only reaching 5% across the 28 countries.

However, these proportions varied a lot between countries. In Tanzania, about 30% of FSW were receiving PrEP last year, and in Zambia, 20% of MSM. In four countries, more than 10% of the eligible key affected populations were receiving PrEP: Lesotho, Zimbabwe, Tanzania and Rwanda.

If PEPFAR PrEP is not replaced, the model estimated there would be 6700 new HIV infections in the first year, 85% of them in key populations: 2900 in MSM, 2000 in FSW, 530 in TGW and 210 in PWID. Seventy per cent would be concentrated in five high-population or high-incidence countries: Tanzania, Nigeria, Zambia, Zimbabwe and Uganda.

The relative increase in the total of new HIV infections over the 28 countries would be 2.1%, but there would be an increase of at least 5% among MSM in eight countries, FSW in six countries, TGW in five, and PWID in two.

The model also did two extra sensitivity analyses. It added in secondary infections occurring in the first five years after PrEP withdrawal, i.e. infections in people who are contacts of those who acquired HIV due to PrEP withdrawal, and this brought the total up to over 10,000. It also calculated the likely total of primary and secondary infections if, as is likely in many African countries, many MSM report being heterosexual: this would bring the total up to almost 16,000, which would represent a 5% increase in new HIV infections.

“We need to ensure stable funding for PrEP that is not influenced by political shifts and new priorities among funders,” Stone commented.