The discovery of a large group of people whose bodies naturally control HIV without taking medication leads to the hope of an ultimate cure, scientists say.
The study found that up to 4% of HIV carriers in the Democratic Republic of Congo could suppress the virus.
Less than 1% of people with HIV can usually do this.
It could serve as a springboard for further research to develop a vaccine or new treatments to tackle the virus that causes AIDS, researchers say.
“When we started seeing the data from the study, we were surprised, but we were also delighted,” Mary Rodgers, the study’s lead scientist, told the BBC.
“It could mean we can cure something,” she said.
The findings, published in eBioMedicine, which is part of the Lancet family of medical journals, looked at samples taken between 1987 and 2019 of people living with HIV.
The team included scientists from the pharmaceutical company Abbott, Université Protestante au Congo, Johns Hopkins, the US National Institute of Allergy and Infectious Diseases and the University of Missouri – Kansas City.
Dr Rodgers, head of Abbott’s global viral surveillance program, said the group in DR Congo was the largest in one country – between 2.7% and 4.3%. Another 1% of people living with HIV in Cameroon have also been identified as controlling the virus well without medication.
“It has never been seen before, usually we find less than 1% of all people with HIV who can naturally suppress the virus.”
Currently, most people with HIV need to use antiretroviral drugs daily to suppress the virus and reduce their viral load.
It is not yet known how the so-called ‘elite controllers’ discovered in DR Congo can suppress their HIV infection.
But Dr Rodgers said it was important to control the virus to understand how the group could maintain low or undetectable viral loads.
However, she stresses the need for more research, referring to previous studies that have shown that this group of people may lose their protection as the disease progresses.
HIV gained worldwide attention in the 1980s. It has since infected 76 million people and 38 million people live with the virus, Abbott says.
It is believed that it originated in the current DR Congo a century ago, and today HIV women outside sub-Saharan Africa become excessive.