Scientists at the Jackson Laboratory developed a cocktail of non-neutralizing antibodies targeting conserved epitopes on influenza A virus’s matrix protein 2 ectodomain, conferring broad protection against multiple flu strains in mice, including avian and swine variants. The therapy maintained efficacy even when administered days post-infection and showed no viral escape after prolonged exposure. This approach challenges the common belief that neutralizing antibodies are required, representing a potential universal flu treatment.