Figure 5.

sa-mRNA bicistronic A/H1N1 vaccines protect viral infection in lung and nose in ferrets

Female domestic ferrets (n = 6) were immunized twice, 3 weeks apart, with 5.0 μg (blue) or 0.5 μg (red) of sa-mRNA H1-N1, 5.0 μg of sa-mRNA H1 (green) or sa-mRNA N1 (purple), or PBS (black) as control. Ferrets were challenged 4 weeks after the second dose with A/Netherland/602/2009 (H1N1) virus at 10⁶ 50% tissue culture infectious dose (TCID₅₀) per animal and killed 4 days later. Lungs and nasal turbinates were collected for recovery of infectious virus. (A) Virus recovery in nose swabs during challenge. (B and C) Total virus recovery from lung (B) and nasal turbinates (C) expressed as TCID₅₀/g of tissue. Each dot represents an individual sample, and the line the geometric mean for the group. The dotted line in each panel represents the lower limit of quantitation for the assay. Statistical analysis by 2-way ANOVA with Tukey’s multiple comparison test was performed using GraphPad Prism 9.1.0. ∗p < 0.05, ∗∗∗∗p < 0.0001.