A study involving more than 2,000 women in Africa has found that the rapid evolution of human immunodeficiency virus (HIV) and widespread access to antiretroviral therapy are slowing down the virus’s ability to cause AIDS.

“Factors that influence the virulence of HIV are of direct relevance to ongoing efforts to contain, and ultimately eradicate, the HIV epidemic,” researchers from University of Oxford said.

The research was carried out in Botswana and South Africa, two countries that have been worst affected by the HIV epidemic.

Across those countries, researchers enrolled over 2,000 women with chronic HIV infection to take part in the study.

The researchers looked at whether the interaction between the body’s natural immune response and HIV leads to the virus becoming less virulent.

The team’s data show that the cost of the body’s adaptation to HIV is that its ability to replicate is significantly reduced, therefore making the virus less virulent.

Viral adaptation to protective gene variants, such as HLA-B*57, is driving down the virulence of transmitted HIV and is thereby contributing to HIV elimination, the findings showed.

The authors also examined the impact of ART on HIV virulence.

They developed a mathematical model, which concluded that selective treatment could weaken the virulence of the virus over time.

“Anything we can do to increase the pressure on HIV in this way may allow scientists to reduce the destructive power of HIV over time,” said lead scientist professor Phillip Goulder from University of Oxford.

The study appeared in the journal Proceedings of the National Academy of Sciences (PNAS).