Twice-Yearly HIV Prevention Injection Shows 100% Efficacy in Major Clinical Trials

A groundbreaking HIV prevention drug has shown extraordinary results in two major clinical trials, with zero new infections among participants.

The drug Lenacapavir, given as a simple injection twice a year, achieved 100% efficacy in preventing HIV transmission in the PURPOSE 1 trial involving 3,200 young women in Uganda and South Africa. A follow-up trial, PURPOSE 2, expanded to 5,000 participants across multiple countries and age groups, showing 99.9% effectiveness.

The twice-yearly injection outperformed daily prevention pills, which though effective, require strict adherence that many find difficult to maintain. The injection also removes the social stigma of being seen taking daily HIV prevention medication.

Named Science Magazine's Breakthrough of the Year in 2024, Lenacapavir works by disrupting the virus's protective shell at a point that remains constant even as HIV mutates—making it a highly reliable target.

Developer Gilead Sciences has committed to providing the drug at cost in low-income regions and licensed generic manufacturers to produce it for approximately £32 per year in 120 countries starting in 2027, making this life-saving prevention widely accessible.