C to E Clinical score (C), body temperature (D), and relative weight (E) during challenge period. Statistical significance between pre-immune and immune sera was determined using Friedman test with Dunn's multiple comparison testing (AAV-HA ##p<0.01; AAV-cHA §§p<0.01; AAV-GFP $p<0.05; $$p<0.01; QIV *p<0.05;). Mean ± SD 