In a 1st, HIV vaccine triggers rare and elusive antibodies in human patients

An HIV vaccine is one step closer to reality following a human trial that produced rare and elusive antibodies, a new study reports. 

Many hurdles stand in the way of an effective HIV vaccine. The virus is a master of evasion, dodging the immune system by coating itself in sugars that resemble those made by the body, said Dr. Barton Haynes, a leader of the recent trial and director of the Duke Human Vaccine Institute. The virus also mutates rapidly, changing its form so that the immune system struggles to make antibodies that can grab hold of it.

A major goal in HIV vaccine development is triggering the production of broadly neutralizing antibodies, which latch onto parts of the virus's outer coating, or envelope, that are very similar between different HIV strains. This makes the antibodies protective against a wide variety of strains, regardless of how they mutate.

The challenge is that "these antibodies, naturally during infection, are very rare to find," said Thomas Hope, a professor of cell and developmental biology who studies HIV at Northwestern University Feinberg School of Medicine. "It takes a couple years of real infection to make these antibodies," said Hope, who was not involved in the new study but has collaborated with some of its authors in the past.

Related: We could end the AIDS epidemic in less than a decade. Here's how.

Vaccines typically work by eliciting a similar immune reaction to what's seen during a real infection. But in the case of HIV, vaccine developers have to dramatically expedite the process, calling forth antibodies in weeks that would usually take years to show up. 

Now, in a study published Friday (May 17) in the journal Cell, scientists have demonstrated that this feat is possible in humans.