Fig. 4: A mixture of four NA-F2A-HA mRNA-LNPs elicits protective immune responses against lethal H1N1, H3N2, and IBV-Yamagata challenges.

a Schematic of vaccination and challenge experiment. Created in BioRender. (Heaton, N. (2024) BioRender.com/k48b864). b–e AUC analysis using cell-based ELISAs against 293Ts transfected with the NA or HA for the indicated virus strains. f–i PRNT₅₀ assays using the indicated viruses in MDCK cells. Any values under the LOD (ULD) (100, dotted line) are shown as 50 for inclusion in the plot. j–l Change in bodyweight through 14 days following lethal challenge with the indicated viruses. Dashed line indicates human endpoint, loss of greater than 25% of starting bodyweight. m–o Percent survival of vaccinated mice following challenge with the indicated viruses. For all experiments, n = 5 mice per group and experiments using sera were all performed with sera taken 21 days post vaccination. mRNA-LNP vaccinated mice all received 10 μg total of their respective vaccine (2.5 μg of each H1N1, H3N2, IBV-V and IBV-Y NA-F2A-HA mRNA-LNPs for ‘four mRNA-LNP’ group), and Flulaval vaccinated mice received 10 μg of a Flulaval dose. For all panels, data are representative of two independent experiments, and are shown as means ± SEM. For all panels including statistics, significance was determined using Kruskal–Wallis test followed by pairwise Wilcoxon rank-sum tests with a Benjamini–Hochberg FDR correction. FDR-corrected p-values are reported above sample groups. Source data are provided as a Source Data file.