Trial offering PrEP to women in South Africa halves HIV incidence

28 June 2021

Study records significant decline in HIV incidence despite only one in four women deciding to take PrEP

Two young women embracing smiling

An HIV prevention trial involving women in South Africa that began offering PrEP in its final year found HIV incidence halved among participants, despite only one in four taking it.

The study is one of the first to show that offering women in South Africa access to PrEP alongside other HIV prevention support, such as counselling and STI tests, can reduce the number of women who get HIV.

The findings come from the ECHO trial, which took place between 2015 and 2018 in Eswatini, Kenya, South Africa, and Zambia. The trial aimed to see whether the risk of getting HIV was different for women (aged 16-35) using one of three long-acting contraceptive methods.

Participants in South Africa were offered daily PrEP pills between March and June 2018. They were asked to take PrEP at the research site (either a clinic or a research centre) rather than taking it at home.

The women’s median age was 23. HIV risks included having more than one sexual partner (reported in 6% of visits), having a partner who had other sexual partners (reported in 10% of visits), having sex without a condom (reported in 65% of visits), and having a new sexual partner (reported in 5% of visits).

Around a quarter (26%) of the 2,124 women offered PrEP took it.

HIV incidence was 4.65% during the trial before PrEP was available. Over the eight months that PrEP was available, HIV incidence fell by more than half to 2.16%.

Similar results were seen when only analysing incidence 180 days before and after PrEP was available (5% incidence compared to 2.29%).

Further analysis found that women who began taking PrEP during the ECHO trial had characteristics linked to increased HIV risk, including having multiple partners and testing positive for an STI. This helps to explain why there was such a big decrease, despite the modest uptake in PrEP use.

The findings suggest that a significant proportion of women at higher risk of HIV will choose to take PrEP when they can access quality services, and as a result, HIV infections will fall. These findings are in line with other PrEP trials, such as HPTN 082 and SEARCH.

It is important to note that PrEP was only available for eight months of the trial, and evidence shows that people are most likely to take PrEP correctly for the first few months. The study did not assess whether the reduction in HIV incidence remained long-term.

Photo credit:
iStock/FG Trade

Written by Hester Phillips