Inserting genetic material directly into human muscle may represent a new approach to HIV vaccine research, according to a study published May 17 in the online version of Nature Medicine and reported on by The Philadelphia Inquirer.

According to the article, researchers from the Children’s Hospital of Philadelphia, Nationwide Children’s Hospital in Ohio and the New England Primate Research Center in Boston used a new technique in monkeys to block simian immunodeficiency virus (SIV), which is closely related to HIV.

Instead of injecting a weakened form of the virus into the monkeys to activate the body’s immune response, the new approach bypasses the immune system. It does this by injecting a genetically modified “carrier” virus, which does not cause disease, into muscular tissue where a protein is then produced that effectively blocks SIV.

Researcher Philip R. Johnson warns that this potential HIV vaccine technique still requires years of testing.

“There is no guarantee that things that work in monkeys will work in humans,” he said.

However, Johnson plans to talk with the U.S. Food and Drug Administration about moving forward with early stage human testing.