New Vaccine Approach Demonstrates Promise in Monkey Trials, Study Says
A new protective HIV vaccine has elicited an antibody response in tests on macaque monkeys, according to a study published in the current issue of the Proceedings of the National Academy of Sciences, Reuters reports. Traditionally, HIV vaccine research has focused on trying to "trai[n]" the body to recognize and attack gp120, an envelope protein located on the surface of HIV. This approach has been largely unsuccessful because candidate vaccines have worked only against the specific strain of HIV that was used in creating the gp120 vaccines. The new vaccine, developed by researchers at the University of Maryland's Institute of Human Virology, builds upon the traditional approach of targeting gp120, but it combines gp120 with CD4, an immune system cell receptor that HIV uses to attach to and invade cells. "In several animals, including monkeys, we were able to generate neutralizing antibodies that are not type-specific but broadly cover various types of HIV," including subtypes A, B, C, D and E, Robert Gallo, co-discoverer of HIV and head of the institute, said. Subtype B is most prevalent in Europe, North and South America and Japan, while A, C, D and E are primarily found in Africa and Asia. Researchers at the institute will test the vaccine in monkeys, which will then be inoculated with either SIV -- a simian cousin of HIV -- or a hybrid of SIV and HIV to determine whether the antibody response is sufficient to prevent infection. Gallo said that if the vaccine is effective in monkeys, he has "no reason to believe that man should be an exception." However, he noted that vaccine candidates have "repeatedly failed" and cautioned against being too optimistic, saying, "[O]ne doesn't make claims without data" (Fox, Reuters, 8/19).This is part of the KHN Morning Briefing, a summary of health policy coverage from major news organizations. Sign up for an email subscription.