Replication in embryonated hen’s eggs is comparable for A/SLOV15 variants.

Embryonated hens eggs were inoculated with 125 TCID₅₀/egg of each A/SLOV15 LAIV, and virus yield was measured by TCID₅₀ assay of allantoic fluid collected every 24-hours post-infection. Mean peak titre achieved by each A/SLOV15 variant across three independent experiments is expressed by the columns. Symbols depict the individual peak titres from each experiment and error bars indicate standard deviation. A/SLOV15 V1 is shown in blue. One-way ANOVA with a Dunnett’s multi-comparison test was conducted to compare A/SLOV15 V1 to all other A/SLOV15 variants. Significant differences are indicated by P values. A/SLOV15 mutants S2-S13 were generated by introducing the following substitutions to wt A/SLOV15 HA (V1) sequence: S2: N125D; S3: D127E; S4: D222G; S5: R223Q; S6: N125D, D127E; S7: D127E, D222G; S8: D127E, R223Q; S9: D222G, R223Q; S10: N125D, D127E, R223Q; S11: D127E, D222G, R223Q; S12: N125D, D127E, D222G, R223Q; S13: N125D, D127E, D222G, R223Q, N380D. All variants contained wt A/SLOV15 NA sequence.