In April 1984, the United States Department of Health and Human Services announced that researchers had discovered the cause of AIDS—and reassured the public that a vaccine could come out within two years. Thirty-one years later, speculation about when an HIV vaccine will finally appear remains as strong as ever. But research released today may point to an alternative—a “novel drug candidate” that is the most potent ever found.
A team of 34 scientists has collaborated to create eCD4-Ig, a compound that could be the future of the fight against HIV. They drew on recent research to develop an artificial protein that inactivates every major strain of HIV—and protects against infections in monkeys exposed to the virus.
To understand how the new protein works, it helps to remember how HIV attacks cells. The virus commandeers the CD4 lymphocyte or “T-helper cell,” a white blood cell that helps prevent infection in a healthy immune system. HIV latches on to two receptors on the CD4 cell and starts inserting its own RNA into the cells, turning the immune system into an HIV-replicating factory.
The research team developed a protein that stops this process in its tracks by binding on to CD4 cells and preventing HIV from taking over—effectively neutralizing the virus. To deliver the protein, the team took a page from HIV’s own playbook. They injected the protein using an innocuous virus that turns the immune system into a receptor-replicating machine instead of one that produces and spreads HIV.
Past research has focused on how to create HIV antibodies that can then be injected as a vaccine. This breakthrough is different, said team lead Michael Farzan in a release:
Our compound is the broadest and most potent entry inhibitor described so far. 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.
Though the method has only been tested on monkeys to date, the next step is to see how it affects humans. The Wall Street Journal’s Betsy McKay reports that the study’s authors hope to begin human trials soon—and that scientists have told her “it should be tested in humans right away.”