New HIV Treatment Strategy Could Permanently Clear the Virus in Infected Newborns

Three HIV treatments used together have completely cleared an HIV-like virus from infected infant monkeys, and more than a year after every drug was stopped the researchers could not find it anywhere in their bodies.

The finding was published on 10 August in the peer-reviewed journal Nature Microbiology by a team led by Oregon Health & Science University, a public medical university in Portland in the United States, working with the California National Primate Research Center.

Eight infant monkeys received the full combination beginning 72 hours after infection. All eight already had virus in their blood at that point, and in none of them could it be found afterwards.

The team had not expected it to work.

"There was no reason to think this would completely clear the virus," said Jonah Sacha, PhD, professor and chief of pathobiology and immunology at the university's Oregon National Primate Research Center, in a statement issued by the university on the day of publication.

Three treatments, one narrow window

Nothing in the combination is new, and that is much of the point.

The first part was antiretroviral therapy, the standard daily medicine that millions of people already take to keep HIV under control. The second was a pair of laboratory-made antibodies that latch onto the virus while it is travelling in the blood, so that less of it reaches new cells.

The third was leronlimab, an experimental antibody that blocks a doorway on the surface of immune cells that the virus uses to get in.

This was not a single injection.

The antibodies were given once, leronlimab was given in nine weekly doses, and the antiretroviral medicine was given every day for 27 weeks. Everything then stopped, at about six months.

Every part had already failed on its own

The strength of the result lies in what came before it in the same study.

The researchers worked through 55 infant monkeys and seven different treatment approaches, and the earlier ones read like a list of near misses.

The antibodies alone, given at 72 hours, held the virus down and then lost it, and it returned in all six animals.

Three weeks of antiretroviral medicine alone did slightly better, leaving two of six with no detectable virus apart from occasional traces. Leronlimab alone, given weekly for months, pushed the virus far down but never cleared it.

Even pairing two of the three was not enough. In those groups the virus came back in four of every six animals once treatment ended.

Only with all three together did it stay away. Something about the combination did what no single part could, and the team says openly that it does not know why.

Proving a virus is really gone

Declaring HIV gone is harder than it sounds, because the virus survives by hiding in a small pool of resting cells that ordinary tests miss.

So the team looked in several ways.

They searched blood and tissue repeatedly for viral genetic material and found none.

They then used a test built to count hidden, intact copies of the virus tucked inside immune cells, and that came back empty too.

Then they tried to force the issue.

Roughly eight months after the last drug was stopped, they stripped out a class of immune cell that normally holds HIV down, which is the standard way of tempting a hidden virus into the open.

In the one surviving untreated animal, and in the two that had received only two of the three treatments, the virus duly reappeared. In the eight, nothing did.

One further detail stood out.

The eight carried no immune memory of the virus at all, no antibodies against it and no virus-fighting cells primed for it.

Their immune systems had, in effect, never properly met it. The regimen also appeared safe in the animals, which gained weight normally and showed no virus-related damage when examined at the end of the study.

The children this is aimed at

About 120,000 children worldwide acquired HIV from their mothers in 2024, according to the Joint United Nations Programme on HIV/AIDS, known as UNAIDS.

That is the lowest figure since the 1980s and a fall of roughly 62 percent since 2010, but it still means hundreds of new infections every day.

About 83 percent of those infections happen in sub-Saharan Africa.

Around 1.38 million children under 15 are living with HIV globally, and roughly 86 percent of them are in the same region, according to the United Nations Children's Fund, UNICEF.

Each of them faces a lifetime of daily medicine, and children have long been harder to reach with testing and treatment than adults.

A course of treatment lasting six months, given in infancy, that ended the need for all of that would change the arithmetic entirely. That is the possibility the study opens.

Why one earlier case should hold the excitement in check

Medicine has stood at this point before and been wrong.

In 2010 a baby girl was born in Mississippi, in the southern United States, to a mother whose HIV was discovered only during labour. Doctors started her on strong antiretroviral treatment within about 30 hours of birth.

She later came off treatment, and for roughly 27 months no virus could be found in her. She was widely described as functionally cured.

Then, in July 2014, at the age of four, the virus reappeared.

That case is why careful researchers avoid the word cure. It showed that a pocket of virus can sit beneath the reach of the best available tests for more than two years and still be there.

The Oregon team acknowledges the same possibility about its own work, noting that deeper sampling of places it did not check, such as bone marrow or the brain and spinal cord, might yet have found something.

What the study cannot say

This was an animal study, and that limit is real.

The animals were infant rhesus macaques, about a month old, and the virus was a laboratory hybrid built to behave like HIV in monkeys rather than HIV itself.

The window was also very narrow.

Treatment began exactly 72 hours after infection, when the virus was spreading into the tissues but had not yet peaked. Whether the combination would still work a week later, or two weeks later, is unknown, and the researchers say it is among the first questions they want to answer.

There is no evidence yet that it would help anyone already living with long-established HIV.

One disclosure belongs here.

Two of the authors, Dr Sacha and Scott Hansen, PhD, hold a significant financial interest in CytoDyn, the company that makes leronlimab and supplied it for the study, and Dr Sacha also sits on the company's scientific advisory board.

The university states that it has reviewed and managed the conflict. The work was funded by the United States National Institutes of Health, which the paper says had no role in the study design, the analysis or the decision to publish.

What moves next

The practical case for speed is that nothing here has to be invented.

Antiretroviral therapy is approved and in use worldwide. Both antibodies and leronlimab are already in human trials, including in newborns, with safety data behind them.

Dr Sacha has said trials in infants could begin immediately.

The university's own account is more cautious, suggesting the first human tests would most likely be in adults recently exposed to HIV before any regimen reached babies.

For now this is a result in eight monkeys, and no treatment guidance anywhere in the world changes because of it.

What it offers is a specific, testable idea about why every previous attempt to clear HIV from newborns has fallen short, and a set of drugs already sitting on the shelf, waiting to be tried.

Source

Sacha JB, Ordonez T, Pandey S, et al. Nat Microbiol. 2026. doi:10.1038/s41564-026-02444-x