To assess the potential influence or interference of pre-existing anti-influenza immunity on immunogenicity and protective ability of the Omicron DelNS1-RBD4N-DAF LAIV, we tested the effect of prior influenza virus infection on our vaccine and found the prime-boost immunization scheme used is able to induce robust SARS-CoV-2 specific antibodies and neutralizing antibodies in mice previously infected with sublethal doses of influenza strains matching the DelNS1-RBD4N-DAF vaccines (Fig. S4A–E). This evidence concerns the gene CD55 and influenza.