Failed HIV Vaccine Trial Raises Many Questions
A promising HIV vaccine trial was recently halted when it appeared that those in the vaccinated group were becoming infected with HIV at a higher rate than those receiving the placebo.
The vaccine used a disabled form of a common-cold virus to carry three synthetically produced HIV genes into the body. It was hoped that those genes would spur the body to unleash an HIV-targeted immune response using so-called “killer” T cells.
Neither the cold virus nor the HIV genes could reproduce, so volunteers could not catch a cold or become infected with HIV directly from the vaccine.
Researchers knew in September that men who were receiving the vaccine were catching HIV at a higher rate than the men who received the dummy shots.
In an initial review, they found 24 HIV infections among 741 men who received at least one dose of the vaccine. That compared to 21 HIV cases among 762 men in the placebo group.
A smaller sample, limited to those who had received at least two vaccinations, found 19 infections in the vaccine group and 11 in the placebo group.
That was enough to pull the plug on the trials Sept. 21.
These are puzzling results.
We’ve known for a long time that HIV thrives when the immune system is stimulated. These results raise the question whether immune system stimulation of any kind from things like vaccines, allergies, or diseases make it more likely for individuals to become infected with HIV.
It also raises ethical questions about testing HIV vaccines if in fact it turns out that they could increase the likelihood of becoming infected.
| Go to Home - Most Recent Posts