A new compartment model of COVID-19 transmission: The broken-link model

We propose a new compartment model of COVID-19 spread, the broken-link model, which includes the effect from unconnected infectious links of the transmission. The traditional SIR-type epidemic models are widely used to analyze the spread status, and the models show the exponential growth of the number of infected people. However, even in the early stage of the spread, it is proven by the actual data that the exponential growth did not occur all over the world. We consider this is caused by the suppression of secondary and higher transmissions of COVID-19. We find that the proposed broken-link model quantitatively describes the mechanism of this suppression and is consistent with the actual data.