Fig. 3

Protection mediated by a prior dengue virus infection on a heterologous or homologous challenge. a Six-week-old female C57BL/6 J mice were treated with 1 mg of antibody to block interferon receptor signaling (IFNAR blocking antibody) and then infected with DENV1 R99142 or DENV2 Puo-218. b Neutralizing antibodies measured by 50% plaque reduction neutralization test (PRNT₅₀) against DENV2 Puo-218. Values are means ± SD from groups of 10 animals. c–e Fifty-five days later, mice were again treated with 1 mg of IFNAR blocking antibody and then infected with DENV2 NGC. c Percent weight loss throughout the study following infection. d Viremia 2 days following infection as determined by plaque assay in Vero cells. e Hematological analysis was performed 7 days post-infection. Values are means ± SD from groups of 5–10 animals. Statistical comparisons were made using a one-way ANOVA with Dunnett’s comparison for all panels except c, which was made to the mock group using a repeated measures mixed-effects model analysis with Dunnett’s correction. *p < 0.05, **p < 0.01, ****p < 0.0001. Studies were performed in one biological replicate, except for b, which was performed in two independent biological replicates. The dotted line represents the limit of detection (LOD); all negative samples were given a value of 0.5 × LOD for statistical purposes