Many have tried and failed to create a vaccine that could prevent infection with HIV. Now, Canadian researchers say they’re working on one that takes a different approach.

Researchers from the University of Western Ontario in London, Ont. say they have developed an HIV vaccine that uses the whole HIV virus, unlike other attempts that have used just certain genes or proteins from the virus.

The virus has been genetically engineered to be “non-pathogenic,” meaning it can’t actually cause HIV in recipients. The idea is the vaccine would prime the body’s T-cells to destroy any cells that might become infected with HIV.

So far, the vaccine has been shown to stimulate a strong immune response in preliminary toxicology tests in lab animals, the university reports. But  it will be several years before researchers know whether it’s effective in humans.

The team announced Tuesday they have just received approval from regulators with the U.S. Food and Drug Administration to begin testing the experimental vaccine on humans. The Phase I clinical trial will begin in January using 40 volunteers who already have HIV. That phase will test the safety of the vaccine.

If all goes well, the next phases of study would test whether the vaccine is actually effective.
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