Major setback in AIDS vaccine

By J. Donald Capra

Published: August 1, 2008

The National Institutes of Health recently canceled a large U.S. vaccine trial, as it was "unlikely to prove effective.” This is the end of a catastrophic series of setbacks that have unfolded in the past year with the failure of what scientists thought was the "last viable possibility for an HIV/AIDS vaccine.”

In mid-2007, as the results trickled in from a worldwide trial, scientists I have known for years were visibly shaken because as the codes were cracked, the vaccine proved ineffective and may even have made the disease worse in those who contracted it after immunization. The last "hope” was that if the trial were conducted in the United States, where a number of variables could be better controlled, there might be an effect.

Harvard's Ronald Desrosiers recently said, "None of the products currently in the pipeline has any reasonable chance of being effective.” Tony Fauci of the NIH opined, "an HIV/AIDS vaccine may never be found.” I know both of these men well, and they are not known for hyperbole.

Twenty-five years into the pandemic, the virus has killed 25 million and now infects 35 million worldwide. In 1984, leading AIDS researchers and government officials said they were optimistic that an HIV vaccine would be available in three years!

There are many paths to a vaccine. The simplest is vaccination against a toxin produced by a bacteria (like tetanus or diphtheria). In retrospect, they were gloriously easy. The second type, generally used against viruses, is "attenuation of a virus” and then "infection.” Since the virus has some of its teeth removed, protection ensues: measles, polio and mumps work this way.

HIV presents basic problems scientists have never encountered. It mutates more than anything we know. It attacks the cells of the immune system and it never "exposes itself,” hiding in cells and infecting by physically touching another cell.

More basic research is needed. The fundamental principles required to build an HIV/AIDS vaccine are simply not known. Federal spending of $500 million a year for 20 years, and at least double that from industry and private philanthropy, has not brought us a desperately needed vaccine.

Without a vaccine, even with vigorous public health efforts, there will likely be more than 2 million new infections each year for the next decade. Thus, in stark terms, the NIH decision, which pushes any practical vaccine out 10 years, means the deaths of more than 20 million people.

Yet there is hope. AIDS is preventable. We need to redouble our efforts in comprehensive prevention education in Oklahoma and worldwide. We have a test for HIV/AIDS; for many, drugs have converted this disease from a death sentence to a difficult but manageable chronic disease. Each year the drugs become more effective with fewer side effects.

Yet, a vaccine to eradicate the pandemic now seems years away and as such presents a humbling situation for scientists and a grim reminder for society of the devastation this disease has brought and will continue to bring to the human race.

Capra is president emeritus of the Oklahoma Medical Research Foundation.

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