Results showed that a small subset of antibodies drawn out by experimental and existing influenza vaccines focus on a site in a part of the flu virus. This is at the base of the influenza virus hemagglutinin (HA) protein. In a press release from The University of Chicago’s Biological Sciences Division, it’s described as “an ‘epitope’ whose significance was not recognized in prior influenza antibody studies.”
“It’s always very exciting to discover a new site of vulnerability on a virus because it paves the way for rational vaccine design,” co-lead author Andrew Ward, Ph.D. said in a press release.
Ward is a professor of Integrative Structural and Computational Biology at Scripps Research.
“It also demonstrates that despite all the years and effort of influenza vaccine research there are still new things to discover.”
“By identifying sites of vulnerability to antibodies that are shared by large numbers of variant influenza strains we can design vaccines that are less affected by viral mutations,” said co-lead author Dr. Patrick Wilson, formerly of The University of Chicago and recently recruited to Weill Cornell Medicine.
“The anchor antibodies we describe bind to such a site. The antibodies themselves can also be developed as drugs with broad therapeutic applications.”
A team of scientists distinguished 358 different antibodies in the blood of people in three groups. They were those who had seasonal influenza vaccine, in a phase I trial for an experimental, universal influenza vaccine or were naturally infected with influenza.
Scientists discovered antibodies recognized a variety of H1 influenza viruses. Those viruses account for many seasonal flu strains. Some antibodies could also recognize pandemic H2 and H5 strains of influenza in lab tests. In mice, antibodies successfully protected against infection by three different H1 influenza viruses.
“In order to increase our protection to these highly mutating viruses, we need to have as many tools as we can,” Han said. “This discovery adds one more highly potent target to our repertoire.”
Those antibodies seem to be relatively common in people. They’re part of a class of antibodies that can be produced by anyone’s body. This is an important consideration when designing a vaccine to generate antibody development.
“The human immune system already has the ability to make antibodies to this epitope, so it’s just a matter of applying modern protein engineering methods to make a vaccine that can induce those antibodies in sufficient numbers,” Guthmiller said.
For more content like this, sign up for the Pulse newsletter here.