First AIDS Vaccine Fails

Nov. 12, 2003 -- Everyone hoped the first AIDS vaccine would hit a home run in large-scale tests. Instead, AIDSVAX struck out.

Findings reported earlier this year showed it didn't work in North America or in Europe. Now results from Thailand show it didn't prevent HIV infection or slow progression of HIV infection to AIDS.

Donald P. Francis, MD, DSc, is president of VaxGen. A hero in the early days of the AIDS epidemic, Francis' prestige and persistence was the main reason AIDSVAX made it to clinical trials. Many researchers warned that AIDSVAX was too simple to work. Francis insisted that with millions of lives at stake, the vaccine should be put to the test.

"The outcome of this trial is one more reminder of how difficult it is to combat HIV and how important it is for the international public health community to redouble the effort to develop an effective vaccine," Francis says in a news release. "Although we are disappointed with the outcome, VaxGen and our Thai collaborators have created a model that can be used around the world for advanced clinical research of an HIV vaccine."

It was hoped that if the vaccine didn't prevent HIV infection, it would at least slow the relentless progression of AIDS. That didn't happen. Despite getting seven vaccine injections, vaccine recipients got no fewer HIV infections than those who got placebo injections. All of the study's 2,546 injection drug users received extensive counseling on how to avoid HIV infection.

Though AIDSVAX is a flop, Francis and his international team of colleagues did prove that it's possible to test an AIDS vaccine in the real world -- and showed how it can be done.

"Although AIDSVAX was found not to work, the trials themselves were a success," Seth Berkeley, president of the International AIDS Vaccine Initiative (IAVI), says in a news release. "Other AIDS vaccine candidates, employing promising design strategies that are different from AIDSVAX's, are in trials and more are being developed."

One of these trials is using AIDSVAX to boost Aventis Pasteur's ALVAC. This HIV vaccine uses a harmless bird pox virus genetically engineered to carry HIV particles. Early studies already are finishing; a larger trial is under way in Thailand.

In addition, some 30 other approaches are being tested in clinical trials -- including 22 approaches that are being fine-tuned as researchers conduct small human tests and take what they've learned back to the lab for further tweaking.