An mRNA vaccine expressing the capsid protein of goose astrovirus elicits protective immunity.

Goose astrovirus (GoAstV) is an emerging pathogen responsible for severe gout in goslings, causing substantial economic losses to the waterfowl industry, with no commercially available vaccines to date. In this study, we developed a novel mRNA vaccine expressing the capsid protein of GoAstV, delivered via lipid nanoparticles (LNPs). The vaccine elicited robust humoral and cellular immune responses in mice, including high titers of GoAstV-specific IgG, IgM, and neutralizing antibodies, significantly increased lymphocyte proliferation capacity, and a Th2-biased cytokine profile. In goslings, the vaccine induced neutralizing antibodies that peaked at four weeks post-immunization and significantly reduced viral shedding following challenge with a virulent GoAstV strain. This is the first report demonstrating the efficacy of an mRNA-based vaccine against GoAstV, highlighting its potential as an innovative strategy for controlling GoAstV infection in geese. Our findings provide a foundation for further development of mRNA vaccines against GoAstV and underscore their promise in addressing emerging viral diseases in poultry.