Temporary ‘circuit breaker’ lockdowns could effectively delay a COVID-19 second wave infection peak to early spring.

Multiple countries are assessing or already implementing short-term “circuit-breaker" lockdowns to suppress recent second- wave surges in COVID-19 cases. We present modelling simulations to quantify the impact and effectiveness of circuit-breaker lockdowns of varying effectiveness. Using UK case data, and assuming a four-week lockdown starting on October 1st, we show that these short-term lockdowns prove effective at postponing a peak in infection numbers to the spring of 2021, allowing an uncoupling from other health pressures that predominantly occur in winter. However, in the absence of any other intervention, such as a vaccination program, the lockdown will not affect the magnitude of the eventual subsequent peak. As such, circuit-breaker lockdowns are a suitable measure to help prevent strain on health services during the winter months, on the understanding that new measures may also be required after such a lockdown to suppress any re-emerging high case numbers.