FIG 1.

Temperature effects on ZIKV, DENV, and CHIKV replication. (A to D) Replication rates for ZIKV in C6/36 cells and titers on day 6 (A), ZIKV in Vero cells and titers on day 7 (B), DENV in C6/36 cells and titers on day 7 (C), and CHIKV in C6/36 cells and titers on day 2 (D). (E and F) Percent maximum titer on day 2 (E) and day 8 (F). C6/36 cells were incubated with ZIKV (MOI, 0.1), DENV (MOI, 0.1), or CHIKV (MOI, 0.005) for 2 h at 28°C, when infectious medium was removed and replaced with fresh medium. The cells were kept at 16°C, 20°C, 24°C, 28°C, 32°C, or 36°C for 10 days. Vero cells were infected with ZIKV (MOI, 0.1) for 1 h at 37°C. The cells were incubated at 28°C, 32°C, 37°C, 39°C, 40°C, or 41°C for 7 days. Supernatants were collected every 24 h and titrated on Vero cells. Titers are given in TCID₅₀ units/mL. Dashed lines represent the limit of detection. Data shown are means ± SEM from three independent replicates for each virus. Bar graphs represent viral titers on the day peak titers were reached at optimal temperature (28°C for C6/36, 37°C for Vero). Statistical differences were determined with a one-way ANOVA on log-transformed data for each experiment. Dunnett’s test was used for multiple comparisons, where the optimal temperature (28°C or 37°C) was compared to all other temperatures. *, P < 0.05; ***, P < 0.001; ****, P < 0.0001.