Fig. 8.

Infected number $I$ for USA. Data is plotted with purple, SEIR solution with brown, and the fractional model $c_1={\lambda }_1=0.9$, $c_2={\lambda }_2=1.15$, $c_3={\lambda }_3=1.2$, $c_4={\lambda }_4=1$ and $b_4={\eta }_4=1.15$ with blue.(For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)