Infant monkeys treated within three days cleared an HIV-like virus completely. Researchers must now show whether human babies can do the same.
Imagine a sunlit maternal health clinic in western Kenya, echoing with the soft, hopeful cries of newborns and the quiet sighs of mothers holding them close. For decades, a positive HIV diagnosis in an infant has meant walking out of that room with a life-altering prescription: HIV medicines every day for life, regular clinic refills across dusty roads and the perpetual, quiet weight of managing a long-term illness.
Now, a study published in the journal Nature Microbiology by researchers at Oregon Health and Science University (OHSU) in the United States offers a breathtaking possibility: that this lifelong story could be stopped before it begins. In baby monkeys, a combination of three treatments, started three days after they were infected with a virus similar to HIV, cleared the infection completely. None of the eight monkeys that received it showed any sign of the virus coming back, even after all treatment was stopped.
The findings come with important caveats. The study was done in monkeys, not human babies. Researchers must still prove that the treatment is safe and works in infants, find out whether it can work if started later than three days, and work out how such expensive, advanced medicines could reach poorer countries such as Kenya.
The stakes are high. According to World Health Organization (WHO) statistics for 2025, around 93,000 children worldwide were diagnosed with HIV, most of them infected by their mothers during pregnancy, childbirth, or breastfeeding. Antiretroviral therapy (ART), the daily HIV medicine, stops HIV from developing into AIDS, but it does not remove the virus from the body. Some of the virus hides in the body’s cells, out of reach of the medicine. These hiding places, known as reservoirs, allow the virus to roar back if a person stops taking treatment.
When the monkeys were one month old, scientists infected them through the mouth with lab-made virus
The OHSU team studied 55 baby rhesus monkeys, both male and female, split into groups to test seven different treatment approaches against untreated monkeys. When the monkeys were about one month old, the scientists infected them through the mouth with SHIV, a lab-made virus that combines parts of HIV and its monkey equivalent. This was designed to copy the way babies are infected around the time of birth.
The team tested three types of treatment, alone and in combination. The first was standard HIV medicine (ART). The second was a pair of lab-made antibodies, known as broadly neutralising antibodies, which latch on to the virus and help the body clear it. The third was leronlimab, an experimental antibody that blocks a doorway on the surface of immune cells, called CCR5, which HIV uses to get inside them. Leronlimab has not yet been approved for treating HIV.
Eight monkeys received all three treatments starting 72 hours after infection, when the virus was already present in their blood. The 72 hours mark when treatment began, but the treatment itself lasted several weeks: one dose of the two antibodies, nine weekly doses of leronlimab, and daily HIV medicine injected under the skin for 27 weeks. After that, all treatment was stopped.
The results were remarkable. Monkeys given one or two of the treatments saw their virus levels drop for a while, but the virus came back. In the group given all three, the virus disappeared.
One treatment alone can slow the virus or shrink its hiding places, but not get rid of them
Over six months of monitoring, researchers found no trace of the virus’s genetic material in the monkeys’ blood. They then removed the monkeys’ CD8 T cells, the immune cells that can keep a hidden virus quiet, to check whether the virus was truly gone or simply being held in check. It still did not return. Finally, 84 weeks after infection, scientists tested tissue from across the monkeys’ bodies and found no virus at all.
Eight monkeys may seem a small number, but the result was a key early test showing the idea can work: the virus never managed to settle in.
Dr Jagmohan Batra, a children’s infectious disease specialist who was not involved in the research, told Medical News Today why combining treatments matters. “A single therapy may control viral replication or decrease the reservoir but does not seem to eliminate it,” he said. In other words, one treatment alone can slow the virus or shrink its hiding places, but not get rid of them.
Dr Jagdish Khubchandani, a public health professor at New Mexico State University who was also not involved, said he remains “cautiously optimistic.” He noted that monkeys’ bodies work like ours in many valuable ways, but using the treatment in human newborns will require careful work on getting the dose right and on spotting infected babies early.
Timing is a further concern. “The longer the infection persists, there are likely more reservoirs established and in more tissue types,” Batra said. Put simply, the longer the virus goes untreated, the more places it finds to hide. He added that the treatment might first be most useful for babies at high risk of catching HIV during birth, while doctors wait for their test results.
Kenya has made extraordinary strides in protecting newborns, yet thousands still catch the virus every year
While the study was done in monkeys, it carries deep meaning for countries such as Kenya, where many babies still catch HIV from their mothers.
Picture Amina, a young mother from Kisumu. When she learned she was living with HIV during her antenatal visits, her immediate fear was not for herself but for the tiny life growing inside her. Thanks to local health agencies and national Prevention of Mother-to-Child Transmission (PMTCT) programmes, Kenya has made extraordinary strides in protecting newborns. Yet thousands of babies still catch the virus every year. For their families, entering the healthcare system has traditionally meant a lifetime of keeping up with daily pills, long journeys to county referral hospitals, and the heavy shadow of stigma.
A short, well-timed course of combined treatment could change everything for families like Amina’s.
Breaking the lifelong cycle: Instead of committing a child to decades of daily medicine, treatment given soon after birth could wipe out the infection before the virus finds places to hide.
For mothers who carry the guilt and worry of passing on the virus, seeing it cleared would bring profound relief
Freeing up clinics: In busy maternal and child health clinics from Kondele to Nairobi, replacing lifelong care with a short course of treatment for newborns would free up staff, time, and medicines for other pressing health needs.
Restoring parental peace of mind: For mothers who carry the guilt and worry of passing on the virus, seeing it cleared from their child would bring profound relief and an unburdened future.
Bringing the treatment to families like Amina’s will take more than human trials. These antibody medicines are complex and costly, so getting them into clinics in poorer countries will require creative global health partnerships and reliable supply systems.
Even with these hurdles, the momentum is undeniable. For the world’s youngest patients, the approach reported by Jonah Sacha, Nancy Haigwood and colleagues represents more than a scientific triumph. It holds out the promise of a future where children born with HIV grow up free of the virus, never remembering what it felt like to be sick.
Dr Madeline Iseren is a pharmacist who comments on topical medical and health issues.
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