September 20, 2002

Spearman discusses HIV-related vaccine advancements

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Heart transplant survivor Michael Prescott is encouraging others to participate in the Oct. 20 Heart Walk on Vanderbilt’s campus. (photo by Dana Johnson)

Spearman discusses HIV-related vaccine advancements

Dr. Paul Spearman, assistant professor of Pediatrics and Microbiology & Immunology, delivered a presentation on the research being done to develop a vaccine to contain HIV and AIDS. The presentation, “New Approaches in HIV Vaccine Development,” was presented during Pediatric Grand Rounds on Sept. 10.

As the AIDS epidemic continues to spread worldwide, physicians and scientists work diligently to find a way to contain the disease and prevent it from taking more lives. A new person is infected with HIV approximately every six seconds. Ninety percent of HIV cases occur in parts of the world with no access to retroviral therapy.

The HIV virus is an envelope virus with particular receptors. Similar to herpes, once the virus infects the cell, it is there forever. Determining a way to contain HIV or even prevent it has proven difficult, Spearman told the group.

The goals for the ideal vaccine include protecting individuals from HIV through sterilizing immunity. An effective method to accomplish this has not yet been discovered. Additional objectives, Spearman explained, include viral suppression — protecting the individuals from HIV-related disease while not preventing infection, and applicability to diverse isolates in individual and distinct populations.

Currently, researchers are encouraged by progress in the development of a vaccine for SIV, or simian immunodeficiency virus. In the last two years, vaccines have been developed that protected macaque monkeys from AIDS. In an experimental population of macaques infected with HIV, all the vaccinated monkeys remained healthy. Those in the control population that were infected all died. Although a safe, effective vaccine for humans is still elusive, experts find the studies being conducted on the macaques to be promising.

In February the canary pox+ gp120 vaccine trial for humans was cancelled because the response to the vaccine was not great enough. However, much was learned during the trials and researchers continue to work doggedly. Spearman is optimistic.

“An HIV vaccine represents hope,” Spearman noted. “More vaccines are being developed, new technology is being developed…there will be more to report in the coming year.”