New HIV drug prevents infection in monkeys

JUPITER, Fla., Feb. 18 (UPI) -- Scientists at the Scripps Research Institute say a newly developed drug designed to combat HIV, the virus that causes AIDS, is strong enough to work as a vaccine.

The anti-HIV agent, eCD4-Ig, has been tested on macaque monkeys who when vaccinated with the drug were able to withstand heavy, repeated doses the animal version of the AIDS virus called SIV (simian immunodeficiency virus). In lab tests, the drug was able to block every strain of HIV-1, HIV-2 and SIV.

The drug's promise was detailed this week in the journal Nature -- the culmination of several years of research by a dozen scientific institutions.

"This is the culmination of more than a decade's worth of work on the biochemistry of how HIV enters cells," Michael Farzan, a professor at the Scripps Research Institute who led the research efforts there, explained in a press release.

The drug eCD4-Ig works by imitating the immune cell receptors where HIV looks to latch on and wreak havoc on the body's ability to fight off infection and disease. In mimicking these receptors, the drug tricks the virus into docking prematurely. Once the virus's docking procedure has been triggered, it can't act again on the real CD4 cells -- the immune system's primary defense.

"Our compound is the broadest and most potent entry inhibitor described so far," Farzan added. "Unlike antibodies, which fail to neutralize a large fraction of HIV-1 strains, our protein has been effective against all strains tested, raising the possibility it could offer an effective HIV vaccine alternative."

Researchers say that unlike ongoing HIV treatments, the new drug could work as a vaccine that offers protection for years. Once injected, the drug binds with muscle tissue and continues to pump out HIV-disarming proteins for years.