On World AIDS Day, good news, however abstract, is more than welcome. That news came in the form of a new study published in the Proceedings of the National Academy of Science which has found that HIV, the human immunodeficiency virus, is actually evolving in a way that makes it harder for the virus to cause AIDS. The research studied 2,000 women in Botswana and South Africa, two countries which have been hit hard by the epidemic.
To reach these conclusions, a team of researchers led by Oxford University's Philip Goulder examined the relationship between the body's immune response and HIV in order to figure out if the disease became less virulent after infection.
Reuters' Kate Kelland reports:
Previous research on HIV has shown that people with a gene known as HLA-B*57 can benefit from a protective effect against HIV and progress more slowly than usual to AIDS.
The scientists found that in Botswana, HIV has evolved to adapt to HLA-B*57 more than in South Africa, so patients no longer benefited from the protective effect. But they also found the cost of this adaptation for HIV is a reduced ability to replicate -- making it less virulent.
The scientists then analyzed the impact on HIV virulence of the wide use of AIDS drugs. Using a mathematical model, they found that treating the sickest HIV patients -- whose immune systems have been weakened by the infection -- accelerates the evolution of variants of HIV with a weaker ability to replicate.
The positive findings are accompanied by the news that the number of people receiving treatment has now exceeded the number of newly infected people, which is an important tipping point in terms of fighting the disease.
Today, approximately 34 million people are living with HIV/AIDS around the world, with 70 percent of new HIV cases occurring in Sub-Saharan Africa. According to the World Health Organization, 24.7 million cases are in the region. Between 2005 and 2013, AIDS-related deaths decreased by almost 40 percent.
"If this process is something we can see continuing as a trend, then the ability of HIV to cause disease will become less and less over time," said Goulder in an interview with Bloomberg Businessweek. "We have the opportunity in HIV to see evolution before our eyes. We haven't ever really been able to view this evolution in so much detail."