Scientists from Institute of Tropical Medicine in Antwerp, compared HIV-1 samples from 1986-89 and 2002-03.
They found the newer samples appeared not to multiply as well, and were more sensitive to drugs - some other studies argue they are becoming more resistant.
The researchers, writing in the journal Aids, stressed their work in no way meant efforts to prevent the spread of HIV should be scaled down.
They were only able to compare 12 samples from each time period, and they were unable fully to tease out any effect that drug therapy may have had on the virus, informs BBC.
For biologists, the idea that HIV-1 might adapt to humans over time and become less harmful is not surprising. A cousin of HIV called the simian immunodeficiency virus (SIV) has adapted to coexist as a relatively harmless passenger virus in certain species of monkeys. But while SIV has infected monkeys for thousands of years, scientists believe HIV-1 jumped into humans from SIV-infected chimpanzees only a few decades ago.
“It helps an organism when it establishes a symbiotic relationship with the host,” said Dr S. Kanury Rao, an immunologist at the International Centre for Genetic Engineering and Biotechnology, Delhi. Humans play host to HIV-1.
Vanham said the experiments were designed to test the hypothesis that over time HIV-1 might be adapting to humans. The researchers will present their findings in the journal AIDS tomorrow, reports the Telegraph.
Foto LIBRAR P.T.