A team of academic and government researchers reports today on a promising new "prime-boost" HIV vaccine approach that is currently on a development fast-track for human clinical trials. This vaccination strategy kept an HIV-like virus in check in monkeys, even when the animals were exposed to very high virus doses months after immunization. The study appears March 9 in Science Express, an online publication of the journal Science.
Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID), which funded the research, praises the recent findings. "This latest study provides some of the best evidence to date that a preventive HIV vaccine may protect against AIDS. Although the vaccine did not prevent infection, it continues to keep the virus at nearly undetectable levels for at least several months. We do not yet know if this vaccine will work in humans, but plans for the necessary clinical studies are under way."
Scientists from Atlanta's Emory University and NIAID combined two vaccines in a strategy they hoped might be effective and then evaluated that strategy in monkeys. Both vaccines were designed against SHIV, a virus containing components of HIV and the related monkey virus, simian immunodeficiency virus (SIV). SHIV mimics HIV infection and causes serious illness in macaque monkeys. The hybrid virus allows researchers to study the reactions of the immune system to the vaccines and the virus.
In the study reported today, 23 of 24 vaccinated monkeys suppressed the virus to nearly undetectable levels during the 20-week follow-up. Virus levels in the one animal were intermittently higher but still more than 100 times lower than those in four control animals that had not received the vaccine. By 28 weeks, all four control animals had developed AIDS-related opportunistic infections and were euthanized, whereas all 24 animals receiving vaccine remain alive and healthy.
The Emory team develope
Contact: Gregory Roa
NIH/National Institute of Allergy and Infectious Diseases