Alternating quarantine for sustainable mitigation of COVID-19.

Lacking a drug or vaccine, the current strategy to contain the COVID-19 pandemic is by means of social distancing, specifically mobility restrictions and lock-downs. Such measures impose a hurtful toll on the economy, and are difficult to sustain for extended periods. The challenge is that selective isolation of the symptomatic patients is insufficient to control SARS-CoV-2, due to its relatively long incubation period, in which individuals experience no symptoms, but may already contribute to the spread. How then do we isolate these \textit{invisible} pre-symptomatic spreaders? Here we propose an alternating quarantine strategy, in which at every instance, half of the population remains under lock-down while the other half continues to be active, maintaining a routine of weekly succession between activity and quarantine. Under this regime, if an individual was exposed during their active week, by the time they complete their quarantine they will, in most cases, begin to exhibit symptoms. Hence this strategy isolates the majority of pre-symptomatic individuals during their infectious phase, leading to a rapid decline in the viral spread - all while sustaining a continuously active economy at $50\%$ capacity.