Figure 1. Neutralizing antibody titers in pups born to PDK53-immunized dams and disease outcome upon challenge with homologous or heterologous DENV2 strain.

(A) Adult A129 mice (n = 5) were immunized with PDK53, and PRNT₅₀ titers against strain 16681 were monitored at the indicated time points. Naive controls (8 wko) were age matched to the first time point. Each data point represents 1 mouse; short horizontal lines represent medians and interquartile ranges. Limit of detection is represented by the horizontal dashed line. (B) PRNT₅₀ titers of pups against strain 16681. Pups (n = 4) born to PDK53-immunized dams were monitored at the indicated ages; age-matched pups born to naive dams served as controls. (C) 16681 viremia. Three-wko pups (n = 4) born to PDK53-immunized or naive dams were infected with 10⁷ PFU of 16681. Viremia was assessed by plaque assay at day 2 after infection. (D) Clinical scores of 3-wko pups born to PDK53-immunized or naive dams following 10⁶ PFU D2Y98P-PP1 challenge. 0, no observable symptoms; 1, ruffled fur; 2, diarrhea; 3, hunching; 4, severe hunching, both eyes shut, lethargy. (E) D2Y98P-PP1 viremia and organ viral loads at day 4 after infection. Medians and interquartile ranges are shown. PRNT₅₀ titers of immune sera were compared using Kruskal-Wallis test; remaining comparisons were done using Mann-Whitney test. *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001; ns, P > 0.05. Data are representative of 2 independent experiments.