By Daniel J. McLaughlin
A decade ago, Timothy Ray Brown - known as the "Berlin patient" - was treated successfully for HIV, following a stem cell transplant.
It has taken until now for a second person, known as the "London patient", to show a similar recovery after the treatment.
The news has been celebrated with scientists saying they are on the right path to cure HIV.
However, the recent development is limited to such a small group of people - and it cannot be used on all HIV patients.
The San Francisco Chronicle reports that the second man "cured of HIV" sparks hope that millions could eventually benefit.
They write that the apparent cure has "rekindled confidence" that scientists will harness the therapy and use it for millions of others in the near future.
The Chronicle spoke to Dr Timothy Henrich, an HIV expert at UC San Francisco, who said the news shows that they are "on the correct path".
He said: "Two cases are always better than one, especially in a field where we don't have a lot of dramatic success.
"The news certainly provides impetus to move on and more further and keep doing good work. It reinforces that we are on the correct path."
Dr Steven Deeks, a professor of HIV, infectious diseases and global medicine at San Francisco General Hospital, told the Chronicle: "We'd begun to wonder if this cure was a one-time thing, but that doesn't appear to be the case.
"This London case to me is a pretty clean repeat of what happened with Timothy Brown [whom Dr Deeks treated several years previously]."
He added: "We have now stronger proof that HIV is potentially very curable. This provides the rationale for pursuing this very aggressively."
Salon's Eric Sawyer, however, warns that the recent development is not a cure for the HIV epidemic, arguing: "Don't believe the hype."
There are four important reasons why it does not offer promise of an impending cure for HIV: it is highly dangerous; it is extremely expensive; it is not scalable; and it is not sustainable.
Sawyer explains that a stem cell transplant - also known as a bone marrow transplant - is never done on patients who only have HIV alone. The treatment is usually reserved for patients who have late-stage cancer and "for whom standard cancer treatments have otherwise failed". It is an extremely dangerous procedure, and it can be lethal.
The Berlin patient almost died from a host donor rejection during his treatment.
It cannot be used on all HIV patients. The treatment has been used on "only a small group of cancer patients failing all other cancer treatment interventions who also have HIV". The two patients, who showed signs of a "cure", also had the CCR5 genetic mutation - it is extremely rare, and it is present only in less than five per cent of Europeans.
Sawyer concludes: "While a cure for HIV would be a dream come true, it would be far more effective for the media to engage in a feeding frenzy spreading information about the importance of HIV testing, the use of PEP and PrEP for preventing HIV infections, and stressing the need for all people who test positive for HIV to begin and remain compliant with their treatment regiment."
The "London patient", a man with HIV, was given a stem cell transplant to treat his blood cancer. He had Hodgkin lymphoma, a cancer of the lymphatic system, a key part of the immune system.
He has no detectable signs of HIV 18 months after stopping his anti-HIV treatment.
According to the NHS, he received a stem cell transplant from a donor to generate new healthy blood cells. They explain: "The stem cells given to the man had a natural mutation that protects against infection from some types of HIV."
They stress that this is not a cure for HIV that can be used widely. "Antiretroviral treatment will remain the main treatment for people with HIV for the foreseeable future," they add.