HIV vaccine in final trials

For the first time in 23 years, a vaccine for the HIV virus has advanced to the final stage of clinical trials.

In a community forum last night, doctors affiliated with Fenway Community Health, a local health care organization specializing in the needs of gay, lesbian, bisexual and transgender patients, explained the intricacies of HIV vaccine research.

“It couldn’t be negative,” said College of Arts and Sciences senior Haley Blaska of the research information.

Two vaccines are currently undergoing clinical trials in the United States. One, produced by pharmaceutical company VaxGen, has reached phase three, the final step on the road to approval by the Food and Drug Administration.

VaxGen’s study is the largest clinical trial of an HIV vaccine, if only because it’s the first to reach the third and final phase of testing.

“We cannot and must not let this virus defeat us,” said Mark Cayabyab, co-chair of the Fenway Community Advisory Board, which acts as liaison between researchers and the Fenway community. “We hope and dream that someday we will eliminate HIV/AIDS, like we have eliminated polio, with a vaccine.”

Still in its infancy, another trial of the drug HVTN Protocol 3 is being conducted in conjunction with Brigham and Women’s Hospital, Beth Israel Hospital and Fenway Community Health.

Dr. Raphael Dolin, an AIDS researcher and professor at Harvard Medical School, described himself as “torn apart” by the desire to believe an HIV vaccine is at hand and the need to maintain a “dispassionate and scientific view.”

“While I share the skepticism of my colleagues in the scientific community, I applaud VaxGen for its effort,” Dolin said.

According to Dolin, “enormous strides” have been made in understanding the causes and origins of the HIV virus. Attempts to treat the disease with so-called “drug cocktails” of protease inhibitors have seen a great deal of success in past years, allowing HIV positive patients to live for years without developing full-blown AIDS.

The cases of African prostitutes, also known as “sex workers,” who remain unaffected by HIV despite their high-risk profession and of uninfected babies born to infected mothers seem to indicate the body can develop defenses to the HIV virus.

However, Dolin said, how these natural immunities develop remains a mystery that hampers the development of an HIV vaccine.

“We don’t have a good model of naturally acquired immunity to HIV,” Dolin said.

Traditional vaccines introduce a non-virulent form of a disease into the body, in effect teaching the patient’s immune system to create antibodies capable of fighting the virus. Parts of the HIV virus are grafted onto a harmless “vector,” in this case a form of smallpox found in canaries, which is then injected into the patient. Doctors stressed this vector does not replicate itself in mammals and poses no threat to humans.

“There really is no danger anyone’s going to develop a canary pox virus,” said Dr. Kenneth Mayer, Medical Director of Research and Evaluation at Fenway Community Health.

Development of an HIV vaccine has been complicated by the lack of knowledge of the virus’ behavior.

The vaccine now being tested solves this problem by adding genetic instructions which boost the body’s production of T-cells, which seek and destroy foreign viruses.

HVTN Protocol 3 is an attempt to combine both approaches in a single inoculation.

Doctors involved with the study adamantly stated the drug is still in the experimental phase and is by no means a cure for AIDS; the VaxGen vaccine has several flaws, including the fact it seems to be effective only against single strains of the HIV virus, which constantly mutates.

“Nobody should sign up for a vaccine trial thinking they’ll get protection from HIV,” said Dr. Daniel Cohen, Associate Medical Director at Fenway Community Health.