Researchers claim a major milestone in the search for a cure for HIV

A patient in London has reportedly been cured of HIV. This is only the second confirmed case of someone becoming completely free of the virus.

What are the details?

The unnamed patient, known only as the "London patient," was cured more than a decade after the "Berlin patient" was confirmed as the first person to be cured of the disease. The London patient has not been off his antiretroviral drugs for 18 months, but has shown no signs of HIV despite regular testing.

The breakthrough came from an incredibly rare genetic mutation. This mutation of the CCR5 gene makes the people who carry it resistant to HIV.

Both men received stem cells from donors with this mutation.

"I feel a sense of responsibility to help the doctors understand how it happened so they can develop the science," the anonymous patient told the New York Times.

In addition to being cured of HIV, he was also cured of Hodgkin's lymphoma, by receiving a bone-marrow transplant from the donor with the gene mutation. The patient called this "surreal" and "overwhelming."

What about a cure for everyone infected?

Unfortunately, this cure still isn't ready to be disseminated to other infected patients. For now, the risks associated with the stem cell transplant are too high to allow this method to be approved for general use. At one point during his treatment, the Berlin patient nearly died and had to be placed in an induced coma.

This method has also only resulted in two confirmed cases of someone being HIV free. According to the New York Times, scientists are currently monitoring 38 HIV positive patients, 32 of whom have been given bone-marrow transplants from a donor with the CCR5 gene mutation.

But while this might not be the end of the road in the search for a cure, it is a crucial step to get there.

"Although it is not a viable large-scale strategy for a cure … these new findings reaffirm our belief that there exists a proof of concept that HIV is curable," Anton Pozniak, the president of the International Aids Society, told The Guardian. "The hope is that this will eventually lead to a safe, cost-effective and easy strategy to achieve these results using gene technology or antibody techniques."