Pre-exposure prophylaxis (PrEP), in the daily oral modality, is highly effective in preventing HIV, but adherence to the medication remains low in Brazil, especially among young people from sexual and gender minorities.

Long-acting injectable PrEP, based on cabotegravir (CAB-LA), has also shown high efficacy against HIV infection in clinical trials, proving promising as an alternative to address the challenges of adherence to daily oral PrEP. However, its effectiveness and implementation data are still limited in the Brazilian Unified Health System (SUS).

A study conducted by Thiago Torres, from the Evandro Chagas National Institute of Infectious Diseases, Fiocruz, in Rio de Janeiro, and the ImPrEP Study Group*, investigated the choice of PrEP (daily oral or long-acting injectable) among young people from Brazilian sexual and gender minorities. The analysis was presented at the 14th Congress of the Brazilian Association of Collective Health (Abrasco), held from November 28 to December 3 in Brasília.

From October 2023 to September 2024, young people aged 18 to 30 chose between daily oral and long-acting injectable PrEP modalities in public services in six Brazilian cities (Manaus, Salvador, Rio de Janeiro, Florianópolis, São Paulo, and Campinas), with half of them receiving an mHealth intervention (a digital tool that provided educational videos on combined HIV prevention). The volunteers were followed for 48 weeks, having the possibility to change the prophylaxis modality during this period.

Of the 1,447 young people included, 83% chose long-acting injectable PrEP and 17% opted for daily oral PrEP. Exposure to the mHealth intervention was associated with the choice of the long-acting injectable modality, while being 18 to 30 years old and having a higher degree of decisional conflict measured on a specific scale contributed to the choice of the daily oral regimen.

Among participants who opted for long-acting injectable PrEP, 6% did not continue in the study during the follow-up period and 0.8% received only the first injection. Of the 5,041 CAB-LA injections administered, 94% were given within the stipulated timeframe, with a maximum of seven days of anticipation or delay.

In total, 44 people switched from long-acting injectable PrEP to daily oral PrEP (64% due to adverse effects) and 21% switched from daily oral PrEP to long-acting injectable PrEP (91% due to fatigue from daily use of tablets). Adherence to long-acting injectable PrEP was higher compared to daily oral PrEP: 96.2% versus 64.1%.

According to the authors, long-acting injectable PrEP substantially improved adherence to prophylaxis, showing promise in addressing this issue. They argue that making different types of PrEP available through the SUS (Brazilian public healthcare system) could be crucial to ending the HIV epidemic in Brazil.

Authors:

Thiago Torres (1), Carolina Coutinho (1), Brenda Hoagland (1), Mayara Secco (1), Marcos Benedetti (1), Cristina Pimenta (1), Ronald Ismério (1), Valdiléa Veloso (1), Beatriz Grinsztejn (1) and ImPrEP Study Group.

(1) Evandro Chagas National Institute of Infectious Diseases, Fiocruz, Rio de Janeiro, Brazil.