A yearly injection designed to prevent HIV has successfully passed its first safety trial, according to research published in The Lancet medical journal.
The medicine, lenacapavir, works by preventing the virus from replicating within cells. If further trials confirm its effectiveness, it could become the longest-lasting HIV prevention method available, reducing the need for daily pills or bimonthly injections currently used for pre-exposure prophylaxis (PrEP).
Richard Angell of the Terrence Higgins Trust described the development as “thrilling and revolutionary,” adding that daily PrEP pills have already transformed HIV prevention efforts. “The potential for a safe annual injectable version of PrEP is equally exciting,” he said.
In a trial involving 40 HIV-negative participants, researchers administered a single intramuscular injection of lenacapavir. The study found no significant adverse effects, and traces of the drug remained in the body for at least 56 weeks.
Presenting their findings at the 2025 Conference on Retroviruses and Opportunistic Infections, researchers noted that an annual PrEP injection could help overcome existing barriers to prevention by improving adoption, adherence, and scalability.
Access to PrEP remains inconsistent, with oral pills still unavailable in prisons, online, or through community pharmacies. “We need to get ready for its rollout now and fund sexual-health clinics to do so,” Angell urged.
Scotland recently approved bimonthly PrEP injections, but England is still awaiting approval from the National Institute for Health and Care Excellence (NICE).
According to 2023 data, approximately 39.9 million people worldwide are living with HIV, with 65% of them in the World Health Organization’s African Region. Global health bodies, including WHO, UNAIDS, and the Global Fund, continue efforts to expand access to prevention and treatment, aiming to end the HIV epidemic by 2030.
