Mucosal vaccination against SARS-CoV-2 using recombinant influenza viruses delivering self-assembling nanoparticles

Abstract

Recombinant influenza viruses are promising vectors that can bolster antibody and resident lymphocyte responses within mucosal sites. This study evaluates recombinant influenza viruses with SARS-CoV-2 RBD genes in eliciting mucosal and systemic responses. Using reverse genetics, we generated replication-competent recombinant influenza viruses carrying heterologous RBD genes in monomeric, trimeric, or ferritin-based nanoparticle forms. Following intranasal immunisation, mice developed potent serological anti-RBD responses, with ferritin nanoparticles superseding monomeric or trimeric RBD responses. While parenteral and mucosal immunisation elicited robust anti-RBD IgG in serum, mucosal immuni..