Before revision:  A standard SIR model with confinement shows that infection spread is inhibited only above a threshold . Confinement induces a slow-down in the expansion phase that does not guarantee an eventual control of the epidemic.
After revision:  A standard SIR model with confinement (SCIR) illustrates how lockdown measures inhibit infection spread only above a threshold . Confinement induces a slow-down in the expansion phase that does not guarantee an eventual control of the epidemic.