Researchers have developed an experimental AIDS vaccine that helps monkeys with a form of the AIDS virus successfully control the disease for more than a year.
Louis Picker and his colleagues said Cytomegalovirus (CMV) works by priming the immune system to quickly attack the HIV virus when it first enters the body, a point at which the virus is most vulnerable.
CMV enables the immune system to be constantly on the alert for HIV.
Picker said he thinks it will be possible to have a vaccine ready to test in people within three years, reports the Daily Mail.
Researchers used different versions of the vaccine against a monkey form of the Aids virus, SIV (Simian Immunodeficiency Virus) with outstanding results.
More than half the rhesus macaques treated responded to the point where even the most sensitive tests detected no signs of SIV.
To date, most of the animals have maintained control over the virus for more than a year, gradually showing no indication that they had ever been infected.
Unvaccinated monkeys infected with SIV went on to develop the monkey equivalent of Aids, caused by the collapse of their immune systems.
The findings suggest the vaccine could be effective enough to rid the body of immunodeficiency virus completely.
Conventional antiretroviral therapies are able to control HIV infection, but cannot clear the virus from its hiding places within the immune system's white blood cells.
"The next step in vaccine development is to test the vaccine candidate in clinical trials in humans. For a human vaccine, the CMV vector would be weakened sufficiently so that it does not cause illness, but will still protect against HIV," said Picker.
CMV belongs to the herpes family of viruses, and like other members of the group never leaves the body once an infection has occurred.
'What's exciting about these findings is that for the first time a vaccine candidate has been able to fully control the virus in some animals,' said Wayne Koff, chief scientific officer at the International AIDS Vaccine Initiative (IAVI), which helped fund the research.
Koff said the findings also suggested the possibility that the immune system may eventually eliminate the virus altogether.
The findings appear in the journal Nature.