Fig. 5: Challenging ChAdOx1-NP + M1-RSVF-vaccinated mice with H1N1.

a Vaccination and challenge schematic for the assessment of the protective capacity of ChAdOx1-NP + M1-RSVF against H1N1 infection and subsequent disease in mice. Mice were prime-boost-vaccinated, then challenged with H1N1, and culled 5 days later with tissues and fluids harvested. Blood sampling was performed 4 weeks post-priming and 3 weeks post-boosting. b Weight change in mice over time post-challenge, as measured by % of pre-challenge weight. The significant difference between IM-IN and IM-IM mouse groups is represented with ## (##=p < 0.01). c Viral load in lungs 5 days post-challenge (number of M gene copies/μg lung RNA (log₁₀)). d H1N1 NP-specific IgG and IgA levels in serum, NWs, BALF and LHS post-challenge, as measured ELISA (log₁₀ EU). Median control values are displayed as dashed lines on graphs. e Levels of antigen-specific CD8⁺ T_RM cells^, and relative levels of antigen-specific CD8⁺ T_EM and T_RM, in BAL and lungs post-challenge. T_RM and T_EM cells were defined as CD3⁺CD8⁺CD44⁺CD62L^-CD103⁺CD69⁺, and CD3⁺CD8⁺CD44⁺CD62L^-, respectively, and positive for influenza pentamer H-2Kd TYQRTALV. In boxplots, a “+” symbol represents the group mean. Two mice in group IM-IM did not have detectable BAL T_RM, and one mouse in group IM-IM did not have detectable Lung T_RM. Group differences for all data were analysed using non-parametric Kruskal-Wallis tests (*=p < 0.05, **=p < 0.01, ***=p < 0.001). For all boxplots, whisker endings represent upper and lower extremes, the box bounds represent upper and lower quartiles, respectively, and the central line represents the group median.