Researchers and scientists are talking more and more about the possibility of a cure. We now know a lot about HIV, as much as certain cancers. There are two types of cure that are talked about – a functional cure and a sterilising cure.
A functional cure would suppress the amount of HIV virus in the body to such low levels it can’t be detected or make you ill – but it would still be present. Some scientists argue that antiretroviral treatment is now effectively a functional cure, but most scientists still see a functional cure suppressing the virus without the need for ongoing antiretroviral treatment.
There are a few examples of people considered to have been functionally cured, such as the Mississipi Baby, but sadly all have subsequently seen the virus re-emerge. Most of these people received antiretroviral treatment very quickly after infection or birth.
A sterilising cure is one where all HIV virus is eradicated from the body, even from hidden reservoirs. There is only one known case of a potentially successful sterilising cure. This occurred in a man called Timothy Brown, also known as the ‘Berlin Patient’.
In 2007-8, Brown had chemotherapy and a bone marrow transplant to treat leukaemia. His transplant also came from someone with natural genetic resistance to HIV. This seems to have cured his HIV but it’s still not fully understood why. Because bone marrow transplants are also very dangerous, this type of transplant is not practical as a cure for others. However, it has given researchers key parts of a blueprint from which to work towards a cure.
Researching for a cure
There are four main research approaches being looked at for a cure:
- ‘Shock and kill’ approaches aim to flush the virus out of its reservoirs and then kill the infected cells.
- Gene editing aims to change immune cells so they can’t be infected by HIV.
- ‘Immune modulation’ is looking for ways to permanently change the immune system to better fight HIV.
- Stem cell transplants, as used in the case of the Berlin patient, aim to completely eliminate a person’s infected immune system and replace with a donor system. This is the most complex and risky approach.
While there have been a number of promising pieces of research, there is no cure currently on the horizon.