Figure 4

Evaluation of neutralization activity of mice sera immunized by tetravalent DENV-LPs. Infectious rates of DENV SRIPs in the presence of control sera were shown in the Supplementary Fig. 4. (a) Neutralizing activity of immunized sera against DENV-1 (D1), -2 (D2), -3 (D3) and -4 (D4) was individually evaluated by relative infectious rate using SRIPs assay based on the average of control, non-immunized mouse sera and was expressed as a relative infectious rate against control (100%) for each serum dilution. Dilution rates of test sera were 1:40 (diagonal lined bars), 1:160 (gray bars) and 1:640 (white bars). Statistical analyses for comparison between infectious rates of immunized (n = 4) and control sera (n = 5) were performed by Welch’s test (*p < 0.05, **p < 0.01). Error bars were drawn based on standard deviation. The dotted line indicates 100% of relative infectious rate based on the mean infectious rate of the control sera. (b) Neutralizing activity of Zika virus NS1 IgG-positive human serum used as a positive control was evaluated as described in (a). The positive control serum was tested in quadruplicate and statistically compared with negative control sera similarly (**p < 0.01).