A multivalent nucleoside-modified mRNA vaccine against all known influenza virus subtypes

(Science) Because we cannot currently predict which subtype of the influenza virus will cause the next pandemic, researchers have made various attempts to produce a “universal” vaccine that could protect people from a wide swathe of subtypes. Although most of these efforts have focused on a limited set of antigens that are shared by many subtypes, an alternate approach has been to generate a multivalent vaccine that would encode all known subtypes. Arevalo et al. took advantage of recent advances in nucleic acid–based vaccine platforms to develop a nucleoside-modified messenger RNA–lipid nanoparticle vaccine encoding hemagglutinin antigens from all 20 known influenza A and B virus subtypes (see the Perspective by Kelvin and Falzarano). This vaccine elicited high levels of cross-reactive and subtype-specific antibodies in both mice and ferrets, which protected these animals from matched and mismatched influenza virus strains. —STS