Fig. 3.

ZIKV and CHIKV antibody responses in IFNAR^−/− female mice and ZIKV_MR766 challenge. a Timeline of vaccination, antibody assays, ZIKV challenge, viremia and survival determinations. b End point IgG ELISA titers against ZIKV and CHIKV 4 weeks post vaccination with 10⁶ pfu of the indicated SCV vaccine. Limit of detection 1 in 30 dilution; ND not detected (n = 5/6 mice per group). SCV-ZIKA/CHIK vaccinated mice had higher ZIKV and CHIKV titers than SCV-control vaccinated mice (all p = 0.009, Kolmogorov–Smirnov tests). (Differences in anti-CHIKV titers between SCV-CHIK and SCV-ZIKA/CHIK were not significant). c Neutralization titers against ZIKV_Natal and ZIKV_MR766 in mice vaccinated with the indicated SCV vaccines (n = 6 per group). (Verses SCV-cont, both p = 0.005, Kolmogorov–Smirnov tests). d Neutralization titers against CHIKV in mice vaccinated with the indicated SCV vaccines (n = 6 per group). (Verses SCV-cont, both p = 0.005, Kolmogorov–Smirnov tests). (Differences in anti-CHIKV titers between SCV-CHIK and SCV-ZIKA/CHIK were not significant). e Viremia after challenge with ZIKV_MR766 (6 weeks post vaccination). Limit of detection 2 log₁₀CCID₅₀/ml. For days 2–4 the viremia in SCV-ZIKA/CHIK vaccinated mice (n = 5/6 per group) was significantly lower than in SCV-control vaccinated mice (all p = 0.009, Kolmogorov–Smirnov tests). Error bars represent standard error of the mean. f Survival of mice described in e. Mice were euthanized when ethically defined end points had been reached. SCV-ZIKA/CHIK vaccinated mice survived significantly longer than SCV-control vaccinated mice (p = 0.001, log rank, Mantel–Cox, test)