No significant difference in immunogenicity between warm-aged and freshly prepared 3HA nanoparticles.

Serum IgG titers from mice 2 weeks after a priming immunization (A) or a boost immunization (B) of 10 μg room temperature-stored 3HA nanoparticles (Aged 1x), 20 μg room temperature-stored 3HA nanoparticles (Aged 2x), 10 μg freshly prepared 3HA nanoparticles (fresh) or 10 μg soluble 3HA (soluble). Each point is the IgG titer of one mouse. (* = p<0.05 by one-way ANOVA).