Fig. 7. Fidelity-variant CHIKV live-attenuated vaccine demonstrates reversion potential in vivo.

LAV candidates were passaged 5 times in triplicate at 10⁴ PFU in the brains of 6-day old suckling CD-1 mice. Three combined replicate passaged and single unpassaged LAVs were inoculated i.c. in 2-day old CD-1 mice and weight (a–b) and survival (c) were monitored. Viruses were sequenced using PrimalSeq and non-synonymous mutations were identified with iVar (d). P < 0.0001 (D), log-rank test, n = 15, 1 experiment. Mean and standard deviation are indicated with data points and error bars (a–b). Passage number and biological replicate are indicated in parentheses for individual samples. The red box indicates a known virulent reversion.