Lenacapavir will slow HIV infections if there's enough of it and it reaches at-risk groups

Lenacapavir may slow HIV infections 'but there's not enough' July 23, 2026For a healthy young woman in South Africa, the greatest risk of HIV may come from someone she wants to trust, but can't. She may not know her partner's HIV status, may not always be able to insist they use a condom, and may have little control over whether he has other partners. There is an option: Daily Pre-Exposure Prophylaxis (PrEP) pills keep antiretroviral drugs in the body at high enough levels to stop HIV before it can establish any infection. But PrEP only works if she keeps taking the medication. Miss too many doses and drug levels can fall too low to provide sufficient protection. She may forget, resent having to take a daily pill, or fear that a partner or relative will find the medication, causing stigma. She may also experience side effects from PrEP or struggle to obtain new supplies. How can lenacapavir help? Taking medication consistently — known as adherence — is a challenge for people with conditions like hypertension and diabetes. With PrEP, however, the difficulty is even greater. "You're asking people who are healthy, who don't have any illness, to take a tablet every day," said Salim Abdool Karim, director and co-founder of the Centre for the AIDS Programme of Research in South Africa. "That's a high bar." "Repeated studies, including our own, show that patients who start taking PrEP, by month three, about half of them have given it up. By the end of the year, you're left with only a handful that are still taking PrEP," Abdool Karim told DW. Lenacapavir sharply reduces that daily burden: It requires just one injection every six months. "That's infinitely easier to do than to remember to take a tablet every day," he said. "For those who receive the injection every six months without fail, it works superbly because adherence is effectively complete." But lenacapavir is still too expensive in some regions and access is low. How does lenacapavir last so long in the body? Most established PrEP drugs block enzymes that allow the virus to reproduce and spread —it uses the enzymes to copy its own genetic material and insert it into a human cell's DNA. Lenacapavir works completely differently. It is the first PrEP drug to target the capsid, a cone-shaped shell that surrounds the viral genetic material. But the capsid is also essential to the virus' replication process — and therefore a promising target. "[Lenacapavir] is the most potent molecule we know of against HIV," Wesley Sundquist, a University of Utah biochemist and leading expert on the HIV capsid, told DW. Sundquist said lenacapavir remains effective over long periods and that it is potent even at low concentrations. "It sets up a little depot that slowly dissolves," said Sundquist. Which groups would benefit from lenacapavir (if they can get it)? Abdool Karim pointed to three groups where HIV incidence remains stubbornly high and greater PrEP uptake is urgently needed: - Adolescent girls and young women in parts of Africa - Younger gay men in the West - Vulnerable gay communities in Eastern Europe and Central Asia In South Africa, a rollout for people at risk began in June 2026, backed by a July 2025 agreement between the drug's developer, Gilead, and a public-private financing organization called the Global Fund. Gilead agreed to supply lenacapavir at no profit to up to 2 million people over three years. Earlier, in October 2024, Gilead also agreed to allow the production of cheaper, generic versions of the drug in 120 resource-limited countries, where HIV infection rates are high. But some countries still lack access to the drug. Latin American countries excluded from lenacapavir deals Melissa Scharwey of Doctors Without Borders said some Latin American countries, including Brazil, Mexico, Peru and Argentina, have been excluded from recent rollouts of lenacapavir, despite their having participated in its clinical trials. Even within eligible countries, vulnerable groups may still be missed, Scharwey told DW. "There's by far not enough of it," said Scharwey, calling on Gilead to increase supply and sell directly to MSF at an affordable price of around $40 per shot. The decisive question in driving down HIV, according to University of Washington epidemiologist Monisha Sharma, is whether the drug reaches the people and places where HIV is spreading most rapidly. "In our modeling of South Africa, Zimbabwe, and western Kenya, providing lenacapavir to approximately 2–4% of the adult population, with targeted uptake among people at greatest risk, averted approximately 12–18% of new infections over ten years," Sharma told DW. Lenacapavir 'unlikely to eliminate HIV on its own' "Lenacapavir could substantially accelerate progress toward lowering incidence, but it is unlikely to eliminate HIV transmission on its own," said Sharma. "This impact is highly dependent on affordable lenacapavir drug prices, efficient distribution channels, and targeted uptake among people with the highest HIV risk," she added. That final condition is what gives Abdool Karim his greatest concern. Lenacapavir can largely solve the adherence problem for people who receive it. It cannot solve the harder problem confronting HIV specialists: identifying and reaching those in greatest danger. "The problem is that those at highest risk need to come forward to take the medication. And often those at the highest risk don't see themselves at risk. That's why they're at risk," said Abdool Karim. "If we cannot reach those at highest risk, then we're not going to make a dent in this epidemic in the manner in which we were hoping." Edited by: Zulfikar Abbany