Researchers are a step closer in developing a vaccine that could provide protection against many types of flu viruses.
This new vaccine will be an antibody based vaccine. The research team from The Scripps Research Institute and Crucell Vaccine Institute in the Netherlands has described three new antibodies that could protect against many types of flu viruses. They say that one of the three antibodies called CR9114 is of special interest because it can provide protection against both influenza A and B strains.
According to Ian A. Wilson, one of the study authors, this antibody is "the only one in the world that we know of that has been found to do this."
"To develop a truly universal flu vaccine or therapy, one needs to be able to provide protection against influenza A and influenza B viruses, and with this report we now have broadly neutralizing antibodies against both," said Ian A. Wilson, the Hansen Professor of Structural Biology at Scripps Research.
Influenza A viruses are more dangerous than influenza B viruses and are more capable of becoming a deadly pandemic.
For the study, researchers gathered large number of antibody samples from volunteers who had been given a seasonal flu vaccine. They then screened all these antibodies to find those that could provide protection against different strains of influenza.
Three antibodies were found, CR8033, CR8071 and CR9114. All three of the antibodies protected against two strains of influenza B. Of these three, CR9114 was found to be effective against influenza A virus.
Researchers found that the antibodies work primarily by binding to virus sites that enable it to attach to a host cell, CR8033 binds to the "head" of the virus while CR8071 works by binding to the base of the virus.
"The unique thing about these two antibodies is that they neutralize flu viruses chiefly by preventing virus particles from exiting infected cells," said Nick Laursen, a research associate in Wilson's laboratory who was a lead author of the study.
The antibody CR9114 works differently as it binds to the virus stem and prevents the virus to change shape and fuse with the host cell.
Researchers will be studying CR9114 in detail because this antibody provides protection against both influenza A and B strains.
“As we move towards design of a universal flu vaccine, we need to find more inclusive assays to screen for antibodies such as CR9114, which may be highly effective but have novel mechanisms for neutralization that cannot be detected by the current methods used in influenza vaccine development,” said Jaap Goudsmit from Crucell Vaccine Institute.