AIDS Drug 'Candidate' Shown To Block Infection By Even The Most Virulent Strains Of HIV

For more than three decades, scientists have tried unsuccessfully to develop an effective vaccine for HIV, the virus that causes AIDS. But now researchers say they have created an experimental drug that may function as a sort of "alternative" vaccine for the virus.

The experimental drug, a protein known as eCD4-IG, blocks infection by keeping the virus from binding to the immune cells that are the virus's target. In tests on monkeys, the drug "candidate" proved to be extremely effective at blocking infection--even with the most virulent strains of HIV and its simian counterpart, SIV.

"Our compound is the broadest and most potent entry inhibitor described so far," Dr. Michael Farzan, a professor at the Scripps Research Institute in Jupiter, Fla. and the leader of the research effort, said in a written statement. "Unlike antibodies, which fail to neutralize a large fraction of HIV-1 strains, our protein has been effective against all strains tested."

Farzan said the protein could offer "an effective HIV vaccine alternative," and other researchers seem to share his optimism.

"What Mike [Farzan] has done very ingeniously is to develop a molecule that attacks HIV in two different spots... that is able to neutralize most if not all strains of HIV," Dr. Philip Johnson, a University of Pennsylvania researcher who was not involved in the research, told Newsweek.

But not everyone is convinced that the protein will work as well in humans as it does in monkeys. Dr. David Baltimore, a Nobel Prize-winning virologist at Caltech in Pasadena, Calif., called the research "impressive" but sounded a note of caution.

"It's perhaps a better construct than the antibodies we've been using, but it's a matter of how it plays out in human trials," he said, according to Science magazine. "I don't think it's easy to tell how that will happen."

Farzan said human trials of the experimental drug could begin within a year, the Wall Street Journal reported.

The research, which involved scientists at more than a dozen research institutions, was published online Feb. 18 in the journal Nature.



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