XK and infection: Although infection with PR8(Ud-HA,NA,PB1) and PR8(Ud-HA,NA,PB2,PB1) viruses had resulted in lower infectious virus yields compared to the corresponding viruses with Udorn NP (Figure 4E), their respective RNP complexes (PPB2UPB1PPAPNP and UPB2UPB1PPAPNP), demonstrated no significant difference in activity (p > 0.05; one-way ANOVA; Figure 5A) to complexes with the Udorn NP (PPB2UPB1PPAUNP and UPB2UPB1PPAUNP).