Why lockdown? Simplified arithmetic tools for decision-makers, health professionals, journalists and the general public to explore containment options for the novel coronavirus

Gerry Killeen; Samson Kiware

The copyright holder for this preprint . https://doi.org/10.1101/2020.04. 15.20066845 doi: medRxiv preprint However, such precise control over real epidemics with such sensitive and extremely curved trajectories, will be unachievable in practice. Even lowering the assumed lock down coverage and effectiveness parameters for a simulated epidemic by only 1% to 68% results in a long drawn out peak that completely overwhelms ICU capacity within 3 years and continues to do so after a decade ( Figure 3A and B) , nevertheless leaving 91% of the population lacking acquired immunity. On the other hand, raising assumed lock down coverage and effectiveness by only 1% to 70% results in a long-drawn out containment trajectory that never reaches the elimination end-game ( Figure 3E and F) because the steady trickle of imported cases sustains transmission. Re-introducing complete containment of imported cases merely results in a more extended version of Figure 2E and F, with elimination taking over 6 years to achieve (Supplementary figure 2) .