Scientists Closing in on AIDS Vaccine Successful simian vaccine marks major advance By Rob Quinn, Newser Staff Posted Jan 5, 2012 3:24 AM CST 6 comments Comments A researcher at the International AIDS Vaccine Initiative laboratory works on samples. (Getty Images) (Newser) – "There's more hope than ever before that an AIDS vaccine might be possible," says the lead author of a study that marks a major advance in the search. The study found that experimental vaccines used on monkeys reduced their susceptibility to the monkey version of HIV by 80%, the Wall Street Journal reports. Vaccinated monkeys that did get infected had less of the virus in their bloodstream than unvaccinated ones, indicating that the vaccination had left them with a more robust immune system. All of the experimental vaccines helped the virus bind to the antibodies that can destroy it. Unlike in other AIDS vaccine experiments, one strain of HIV was used for the vaccine and another was used on the monkeys. "This type of protection, and the extent of protection, in non-human primates has not been previously seen," said the lead researcher. The researchers plan to test a human-adapted version of one of the vaccines on people both in the US and in African countries with very high HIV infection rates.