However, Gupta was cautious about the results released on Tuesday (March 5) and warned: "It's too early to say he's cured".
Researchers are tracking other HIV/AIDS patients who have received bone marrow transplants from donors with the same mutation that cured the Berlin patient. Since discontinuing ART in late 2017, the London patient has shown no trace of the virus. But Brown, now 52, continues to live HIV-free today. The patient remained on anti-HIV drugs to prevent the virus from replicating for almost 1.5 years after the transplant; because HIV tends to hide in cells in a dormant phase and reactivate years later, Gupta wanted to be sure that as much of the virus as possible was destroyed with the drugs.
It worked. The Berlin patient, later identified as an American, Timothy Ray Brown, is the first and only person to be "cured" of HIV.
Both the first patient to be cured of H.I.V., Timothy Ray Brown, who is now 52 and was cured in 2007, and the new patient, whom scientists refer to as the "London patient," were afflicted with forms of cancer and were given bone-marrow transplants meant to treat their cancers, not the H.I.V virus, according to The New York Times.
More than 20 years after scientists announced that we had the medical resources to treat HIV effectively, around 40 percent of people living with HIV globally are still unable to access this life-saving treatment.
Understanding how the body can naturally resist the infection does offer up hope of this, even if it is still a long way off.
Later in 2012, he was diagnosed with advanced Hodgkin's Lymphoma. People who have two mutated copies of the CCR5 allele are resistant to the HIV-1 virus strain that uses this receptor, as the virus can not enter host cells.
There are around 22,000 people who are known to have the CCR5 mutation that makes their white blood cells immune to HIV. To eliminate the virus, you'd have to kill every single infected cell in a person's body.
The man - who wishes to remain anonymous - was given stem cells from a donor with genetic resistance to the disease and he has now been in long term remission for 18 months without medication. HIV is at its most unsafe when it is actively replicating, furiously producing as many copies of itself as possible so it can penetrate immune cells and spread infection. That's key because HIV uses that receptor to gain entry into the cells.
Most experts say it is inconceivable such treatments could be a way of curing all patients.
"At the moment the procedure still carries too much risk to be used in patients who are otherwise well". "It shows the Berlin patient was not just a one-off, that this is a rational approach in limited circumstances", said Daniel Kuritzkes, chief of infectious diseases at Brigham and Women's Hospital, who was not involved in the study. About 37 million people around the world have the viral infection.