A new HIV vaccine has just entered human trials. The vaccine has been shown to prevent transmission of the virus to two-thirds of monkeys in lab trials, and will now be tested on 2,600 women in southern Africa. Though the HIV vaccine has been successful in monkey tests, there’s no guarantee that its success will carry over to humans.
The trial, which has been called “Imbokodo,” after the isiZulu word for “rock,” is starting soon, though we likely won’t know the results until 2021 or 2022. While things look good for the Imbokodo trial, promising HIV vaccine trials have ended up failing at the human stage before.
In 2009, the vaccine RV144 also progressed to the human testing level. Unfortunately, RV144 was shown to be effective in humans just over 30% of the time, which wasn’t successful enough to put further research into the drug.
A smaller human study with the new HIV vaccine showed that it was safe for humans. Five members of the study, out of a total 393, reported minor side-effects like stomach pain, diarrhea, dizziness or back pain. This smaller study also demonstrated that the HIV vaccine “induced robust immune responses in humans,” according to study leader Dan Barouch of Harvard Medical School.
In the 40 years of the HIV epidemic, the drug in the upcoming Imbokodo trial is only the fifth HIV vaccine to go to human trials. In theory, if the vaccine works, people could just go and get a shot for HIV, the same way they do for many other diseases like mumps, rubella or polio.
Currently, pre-exposure prophylaxis, better known as PrEP, is the best resource for preventing HIV. PrEP has shown to be at least 98% effective in stopping HIV. And for those who are HIV positive, medication is available to lower the viral load to undetectable levels. And, of course, undetectable equals untransmittable.