Scientists at Oregon Health and Science University (OHSU) have developed a promising new human immunodeficiency virus (HIV) vaccine that could not only control but also cure the disease.

While taking a common approach of testing the vaccine in 16 monkeys infected with simian immunodeficiency virus (SIV), a close relative of HIV, the researchers found that nine of the monkeys were protected from the disease. The new vaccine also did something completely unprecedented: the monkeys’ immune systems generated white blood cells that were able to hunt down the infection and eliminate it.

“They took the cytomegalovirus genome and put some HIV protein genes inside the cytomegalovirus genome,” Associate Professor of Biochemistry Katherine Walstrom explained. “Then they infected the monkeys with the hybrid virus. The approach seems very clever.”

Using a virus as the delivery vehicle for the HIV genes allows the body to develop antibodies, which destroy HIV before it can reach tissues and begin replicating, effectively intercepting the infection.

“Through this method we were able to teach the monkey’s body to better ‘prepare its defenses’ to combat the disease,” Dr. Louis J. Picker, associate director of the OHSU Vaccine and Gene Therapy Institute, said in a press release. “Our vaccine mobilized a T-cell response that was able to overtake the SIV invaders in 50 percent of the cases treated.”

Despite the encouraging results, the new vaccine is far from being available at local pharmacies. Results with rhesus monkeys do not guarantee that the human version of the vaccine will be viable.

“The only problem is, it only worked with half the monkeys. And they don’t know the difference between the ones where it worked and where it didn’t,” Walstrom said. “They should be able to look at the cells or check their genomes and see what the difference is.”

It could take up to three years to get a human version of the vaccine ready for trials.