Lipid nanoparticles-mRNA based on the consensus sequences of avian coronavirus S1 and N genes protect animals against multiple viral infections.

Lipid nanoparticles-mRNA play important roles in SARS-CoV-2 infection control. Avian coronavirus infectious bronchitis virus (IBV) comprises eight genotypes with a lack of cross-protection, causing severe economic losses to the poultry industry. Using immunoinformatics methods, five consensus sequence antigens against prevalent IBV strains were designed. Four monovalent lipid nanoparticles-mRNA (GI-19, GI-13, GI-7, GVI-1) and one quadrivalent lipid nanoparticles-mRNA were constructed to develop a broad-spectrum IBV vaccine. The safety and biodistribution of the lipid nanoparticles-mRNA were evaluated in SPF chickens and confirmed that it induced a strong and durable immune response. The lipid nanoparticles-mRNA efficacy in SPF chickens was verified in infection assays with four genotypes of IBV strains, the results showed that immunization with a 10 µg dose provided complete protection for the chickens, while immunization with a 5 µg dose reduced disease severity, organ damage, and mortality, and inhibited viral replication and shedding. Our results indicate that these Lipid nanoparticles-mRNA are immunogenic and protective in preclinical animal models. These data can provide a basis for IBV prevention and control and the development of mRNA vaccines against other prevalent viruses.