COVID-19 pandemic: Impact of lockdown, contact and non-contact transmissions on infection dynamics

Shovonlal Roy

To demonstrate the secondary-peak dynamics, let us consider the best scenario out of those shown in (Fig. 2) , i.e, both non-contact and contact transmission rates are reduced by 75% throughout the lockdown period. Under such an optimistic scenario, the evolution of secondary peak, its height, time of occurrence and duration solely depend on the duration of lockdown (see, green lines in Fig. 3 ). For example, with a hypothetical health-service capacity equal to 30% of the noaction peak, the first 30 days of lockdown show significant reduction in the infection cases (see, red and green lines in the first window, Fig. 3) , giving a false impression that the subsequent infection cases will stay below the capacity. But once the lockdown is fully lifted, the infection cases spike rapidly over a short time, and the peak goes beyond the capacity, almost nearing the noaction peak. This scenario demonstrates the ultimate failure of the suppression measures as a consequence of premature end of lockdown.