BETHESDA, Md., July 26 (UPI) -- U.S. National Institute of Health researchers say they have found flu viruses can swap many genes more rapidly than thought to make new resistant strains.
Scientists previously believed gene swapping progressed gradually from season to season, the BBC reported. But the NIH team found, instead, influenza A exchanged several genes at once, thereby causing sudden and major changes to the virus.
The findings, published in the journal PLOS Biology, suggest strains could vary widely each season, making influenza potentially harder to treat.
The findings also increase concerns about bird flu mutating to spread readily between humans, the BBC said.