Flu viruses mutate rapidly, meaning that vaccines against the flu have to be continually updated to target the latest strains. Moreover, antiviral medications to combat flu sometimes become ineffective because of viral mutations. Thus, finding a so-called universal flu vaccine that could be used against a wide range of viruses over a longer period of time has been a long-held dream of medical experts and the subject of a lot of research.
Scientists reported this week that they have taken another step toward a possible universal flu vaccine. They discovered a target on the influenza A virus that has not changed much -- unlike other regions of the virus -- called influenza matrix 2 protein (M2e). The researchers then found rare, naturally occurring antibodies in humans that target the protein. When these antibodies were given to mice infected with influenza, 60% to 80% recovered compared to a 10% survival rate in the untreated mice. The antibodies protected against two influenza strains: seasonal human H1N1 and an avian flu, H5N1.
The study was completed by researchers at the University of Wisconsin-Madison, University of Tokyo, Johns Hopkins University and Theraclone Sciences of Seattle. It was published Monday in the Proceedings of the National Academy of Sciences.
While humans can produce these antibodies against the M2 protein as part of the immune system's natural response, levels appear to be too low to trigger enough protection. However therapeutic levels of antibodies might create the necessary protection.
-- Shari Roan
Photo credit: Advanced Cell Technology Inc.