Fig. 5

The impacts of various nucleic acid screening schemes on the COVID-19 epidemic in Yangzhou and Xi’an. The specific schemes are: Remain the first half screenings in Yangzhou (remain the screenings before 22/1/1 in Xi’an); Remain the screenings every other two days; Remain the last half screenings in Yangzhou (remain the screenings after 22/1/1 in Xi’an). The other parameter values are fixed as those listed in Table 1