About 40 million people worldwide currently live with HIV. Thanks to modern treatment cocktails, the disease is no longer a death sentence, but it still requires constant medication, for life.
Now, two new clinical trials from around the world suggest a possibility not seen until now: “Functional cure” — a state in which the body keeps the virus under control over time, without an ongoing need for medication.
The two studies, conducted in South Africa, the UK and Denmark, used infusions of engineered monoclonal antibodies (bNAbs – broadly neutralizing antibodies). In some of the participants, the level of the virus in the blood remained undetectable for months and even years after they stopped taking antiretroviral treatment.
What is “functional cure” and why is it not a full cure?
HIV is one of the most sophisticated viruses humanity has had to confront. It replicates quickly, mutates, and hides in dormant cells so that the immune system cannot detect it. Therefore, a complete cure — the full disappearance of the virus from the body — has almost never been achieved until today, except in rare cases involving special bone marrow transplants.
A “functional cure” is a more modest yet dramatic goal. The virus still exists in the body at very low levels, but:
• It does not replicate significantly
• It does not cause disease
• One can remain without medication for long periods — under close medical supervision.
This is similar to what is seen in a very rare group of HIV carriers called “elite controllers” — less than 1% — who manage to control the virus without treatment. The goal of current science is to replicate this special immune response through medical means.
Two trials, two continents — and one encouraging picture
FRESH trial — South Africa
In the FRESH study, led by Prof. Thumbi Ndung’u, 20 young women from South Africa participated; they had been infected with HIV in the past and began antiretroviral treatment within three days of infection — extremely rare in real life.
• All participants received an infusion of two engineered antibodies chosen specifically against a common HIV strain in Africa (HIV-1 clade C).
• After the infusion, the medication was stopped, and the women were placed under close monitoring.
The results:
In 6 out of 20 women, the virus remained suppressed for at least 48 weeks.
In 4 of them — remission lasted more than a year, and one woman is still in remission without treatment even after about two and a half years.
RIO trial — UK and Denmark
In the RIO trial, led by Prof. Sarah Fidler of Imperial College London, 34 men participated, most of them white and in their 40s, who lived with HIV-1 clade B and were exposed to medication shortly after infection.
• They received a different pair of broadly neutralizing antibodies that had been extensively studied before.
• It was decided to stop the medication and monitor the virus.
The results:
• In 22 out of 34 participants, there was no viral rebound for 20 weeks.
• They received an additional dose of antibodies.
• After 96 weeks — long after the antibodies had already disappeared from the body — 6 of them still maintained a low viral load and did not require ongoing treatment.
In the control group, which received only a saline infusion, most participants had to return to medication within 4–6 weeks.
How do the antibodies work — and what is so special about them?
A small number of HIV carriers, after many years of infection, naturally develop particularly strong antibodies capable of neutralizing a wide variety of strains — these are the bNAbs.
The antibodies in the FRESH and RIO trials are engineered and stronger versions of these.
They act on several levels:
• They bind to critical and stable parts of the virus envelope — parts that the virus cannot easily “change” without losing its ability to infect.
• They mark infected cells for the immune system, encouraging CD8+ T cells to arrive and kill them.
• They apparently create an “immune memory” — so that the body continues to control the virus even after the antibodies have already broken down.
In the RIO study, another exciting hint emerged: It appears that the treatment also affects the dormant viral reservoirs, which hide in cells and are inactive. Until today, most treatments have not succeeded in affecting them.
In the FRESH study, the researchers also added another drug — vesatolimod — designed to “wake up” dormant viruses so that the immune system and antibodies can identify and destroy them.
Who will benefit from this in the future — and what are the limitations?
It is important to emphasize:
• These are proof-of-concept trials with only dozens of participants.
• The researchers themselves are cautious and do not declare a “cure,” but rather long-term control of the virus.
What does emerge from the data?
• The chance for prolonged remission is higher when treatment begins very early after infection — before a large reservoir of dormant viruses forms.
• But there is hope that chronic carriers, who began treatment later, may also benefit in the future from similar strategies — possibly in combination with additional drugs that activate dormant reservoirs.
The next step is larger and more diverse trials that will examine:
• Different combinations of antibodies,
• Dosages and timing,
• And whether a much higher percentage of carriers can achieve prolonged remission.
What does this mean for people living with HIV today?
At this stage, the new treatments are not part of clinical routine, and standard antiretrovirals continue to be the first, effective and safe line of treatment.
But the message from the studies is clear:
• The immune system can, under certain conditions, learn to control HIV.
• Engineered antibodies can serve as a “therapeutic vaccine” — not to prevent infection, but to control the disease.
• The future of HIV may gradually shift from a chronic disease requiring daily medication — to a situation in which some patients can achieve long periods of remission without medication.
Until that happens, the recommendation remains: Get tested, diagnose early, begin treatment on time, and stay in follow-up — this is still the strongest tool we have today.