Paving the way for an AIDS vaccine, scientists have discovered two potent antibodies, the strongest of which can neutralize 91 percent of HIV strains.
Researchers from the Vaccine Research Center at the National Institute of Allergy and Infectious Diseases discovered the antibodies in the cells of a 60-year-old African-American gay man, whose body made the antibodies naturally.
“We have used our knowledge of the structure of a virus—in this case, the outer surface of HIV—to refine molecular tools that pinpoint the vulnerable spot on the virus and guide us to antibodies that attach to this spot, blocking the virus from infecting cells,” VRC director Gary Nabel said in a statement.
Last year, an HIV vaccine demonstrated roughly 30 percent efficacy. This new discovery triples the potency.
The announcement comes just over a week before the International AIDS Conference in Vienna.
The scientists found the antibodies, named VRC01 and VRC02, using a molecular device they developed — an HIV protein that the scientists modified so it would react only with antibodies specific to the site where the virus binds to cells it infects.
The researchers were able to determine the atomic-level structure of VRC01 when it’s attached to HIV, allowing them to design components of a potential vaccine that could teach the human immune system to make similar antibodies that could feasibly prevent infection by the vast majority of HIV strains worldwide.
The United Nations has estimated that more than 33 million people had HIV in 2008. An estimated 2.7 million contracted the virus that year.
One question is whether scientists will be able to successfully use the antibodies to develop a vaccine to protect against AIDS.
Another is how quickly the antibodies can influence the human body to produce its own. It’s entirely possible that they could take months or years — another hurdle.
For now, the researchers plan to test the new antibodies in several ways. According to the Journal report, that includes:
- Directly administering them like a drug;
- Applying them as a “microbicide” gel before sexual intercourse;
- Boosting an infected patient’s existing drug regimen.
To begin walking down that path, the VRC has contracted with a company to produce an antibody that’s safe for humans.
The research was published Thursday in the online edition of the journal Science.