Worrying Signals Emerge As Bird Flu Gains Resistance Mutation

Two new studies released in 2025 provide a mixed picture of how well our current antivirals are holding up against H5N1, the highly pathogenic bird flu virus that continues to spill over into mammals and humans. The good news: H5N1 viruses from recent human cases remain susceptible to frontline antiviral drugs. More concerning is a resistance mutation that emerged and spread rapidly during a poultry outbreak in Canada, raising flags about the virus’s potential to evolve past our…