Figure 4.

Nucleoside-modified OspA mRNA-LNP vaccination generates long-term antibody responses in mice

(A) Mice were vaccinated intramuscularly with a single dose of 3 μg of OspA or Luc mRNA-LNP or 1 μg of rOspA + alum (represented by upward arrow) and bled retro-orbitally at 2 weeks (represented by blood droplet). Mice were bled again at 4 weeks and boosted with the same vaccine doses and then subsequently bled up to 24 weeks. (B) OspA-specific IgG endpoint titers from OspA mRNA-LNP-immunized mice are compared to values from animals immunized with 3 μg Luc or 1 μg rOspA + alum (and boosted with same dose at 4 weeks). Each symbol represents one animal, and data represent mean ± SEM (n = 9–10 mice per group). The horizontal dotted line represents the limit of detection. Titers below the limit of detection are reported as half of the limit of detection. Data from two independent experiments are shown. Statistical analysis: one-way ANOVA with Bonferroni correction of log transformed data, ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001.