HIV affects tens of millions of people globally and while the disease is no longer the automatic death sentence it once was, patients need to take medication for life.
Now an international team of researchers believe they may have a third patient who no longer shows sign of infection after undergoing a different medicine regimen.
The patient, a 34-year-old Brazilian who has not been named, was diagnosed with HIV in 2012.
As part of the study, he was given several potent antiviral drugs, including maraviroc and dolutegravir, to see if they could help him rid the virus from his body.
He has now gone more than 57 weeks with no HIV treatment and he continues to test negative for HIV antibodies.
Ricardo Diaz, an infectious diseases expert at the University of Sao Paulo, said the patient could be considered to be free of the disease.
"The significance for me is that we had a patient that was on treatment and he is now controlling the virus without treatment," he told AFP.
"We're not able to detect the virus and he's losing the specific response to the virus - if you don't have antibodies then you don't have antigens."
The United Nations said Monday that 1.7 million people contracted HIV last year and there are now more than 40 million people living with it.
Diaz said his team's treatment method, which needs further research, was a more ethical avenue for gravely ill HIV sufferers than the bone-marrow transplant route.
"They come with a high mortality rate, there have been a series of patients who have either died from the procedures or it didn't work," he said.
Sharon Lewin, co-Chair of the International AIDS Society Initiative Towards an HIV Cure and director of the Doherty Institute for Infection and Immunity in Melbourne, said Diaz's findings were "very interesting".
She struck a note of caution however, due to the study's limitations.
She noted that the Brazil patients' antibody test had gotten weaker over time - suggesting a diminishing immune response.
"This is very unusual to see in someone off antivirals," she said.
"The Berlin and London Patients may be the only exceptions. This very provocative data needs more in-depth analysis."