Fig 1.
Swelling of the ipsilateral footpads of A129 mice after infection with 104 PFU of wild-type CHIKV, or the 181/clone25 or CHIKV/IRES vaccine strains delivered in the footpad.
Statistical analysis was performed with one-way ANOVA. Single asterisks indicate p<0.05. Double asterisks indicate p<0.001.
Fig 2.
Mean viral loads in A129 mice after infection with 104 PFU of wild-type CHIKV, or the 181/clone25 or CHIKV/IRES vaccine candidate strains delivered in the footpad.
The limit of detection of the plaque assays was 60 PFU/g or ml. Data were analyzed by one-way ANOVA with a Bonferroni post hoc test for pairwise comparisons.
Fig 3.
Representative histopathologic spleen lesions in A129 mice after infection with 104 PFU of wild-type CHIKV, or the 181/clone25 or CHIKV/IRES vaccine candidate strains delivered in the footpad.
Images for CHIKV/IRES, 181/clone25 and PBS are from 3 days post-infection. Green arrows indicate the deposition of proteinacious debris.
Fig 4.
Representative histopathologic liver lesions in A129 mice after infection with 104 PFU of wild-type CHIKV, or the 181/clone25 or CHIKV/IRES vaccine candidate strains delivered in the footpad.
Images for CHIKV/IRES, 181/clone25 and PBS are from 3 days post-infection. Green arrows indicate hepatic lesions.
Fig 5.
Representative leg muscle histopathologic lesions in A129 mice 3 days after infection with 104 PFU of wild-type CHIKV, or the 181/clone25 or CHIKV/IRES vaccine candidate strains delivered in the footpad.
Green arrows indicate sites of focal myositis.
Fig 6.
Representative leg muscle histopathologic lesions in A129 mice 14 days after infection with 104 PFU of the 181/clone25 or CHIKV/IRES vaccine candidate strains or PBS delivered in the footpad.
Green arrows indicate cellular infiltrate and moderate myositis.
Fig 7.
A. Titers of CHIKV vaccine candidate strains in the brains of 2-day-old A129 mice after serial passages. B. Representative plaque morphology of mouse-passaged CHIKV vaccine strains. Data was analyzed by one-way ANOVA with a Bonferroni post hoc test for pairwise comparisons.
Fig 8.
A. Weight change, B. Footpad swelling, and; C. Survival of 6-7-week-old A129 mice inoculated intradermally in the footpad with 104 PFU of wt CHIKV, parent vaccine strains, or 5th intracranial passage vaccine strains from in duplicate, serial passage series (A and B).
Statistical analysis for panels A and B was performed with one-way ANOVA. Single asterisks indicate p<0.05. Double asterisks indicate p<0.001. Statistical analysis for panel 8C was completed by Kaplan Meier.
Table 1.
Consensus substitutions acquired by the 181/clone25 vaccine strain during serial mouse passages.
Fig 9.
Mortality in 10-week-old A129 mice after infection in the footpad with 104 PFU of wt-CHIKV or wt-CHIKV/FfLuc.
Statistical analysis was performed by Kaplan Meier.