Before Wednesday, only one man in 2008 was able to completely rid himself of HIV. Now two other men have been announced HIV free. The ‘Berlin Patient’ was cured of HIV after he received a total stem-cell blood transplant to treat his aggressive blood cancer. Getting rid of his HIV was just a side effect, and to Timothy Ray Brown, the ‘Berlin Patient’ was considered a “medical unicorn” as doctors failed to cure HIV long term for other patients. The two other men, the ‘London patient’ and the ‘Düsseldorf patient,’ have been cleared of HIV, the AIDS causing disease, for at least 18 months.

There is one thing in common with the patients. They all received a stem-cell transplant to treat a form of blood cancer. A stem-cell is able to become a bone, muscle, cartilage and other specialized types of cells; they have the potential to treat many diseases, including Parkinson’s, Alzheimer’s, diabetes and cancer. In the future, they could be used to regenerate organs. And transplants of these cells can be dangerous as your diseased cells must be destroyed with high-dose chemotherapy and/or radiation therapy. What makes the transplants that the three patients received special is their donors had a mutation in their CCR5, a gene that makes them naturally resistant to HIV.

Is this a cure for HIV? The short answer is no. Giving everyone with HIVs a stem-cell transplant would be dangerous and expensive and might not be entirely effective. We must wait to see if the two new patients are cured for the long term. These two patients are still important though as it seems they were able to reproduce the results of the ‘London Patient’ who has been considered HIV free for almost 11 years. This means that the treatment of the ‘London patient’ wasn’t a fluke. Scientists will continue to research and study which means there might be a cure to HIV and eventually AIDS in the near future.