The spread of infection can be simulated using System Dynamics (SD) models such as the SIR model. A simulator, based on this type of simplified models (cf. citation below), is provided at this link. Although very basic, the ‘sim’ can provide useful insights into the dynamics of Covid-19 propagation.
“Epidemic modelling is extremely complex, and small changes in the way it’s done can have huge impacts on the results.” — Kathryn Snow