Fast intermittent lock-down intervals with regular period are suggested as a COVID-19 exit strategy from the widely adopted policy of total lock-down. Many proposed exit strategies have risks and uncertainties which could lead to a second wave of infection 1 , 2 . We demonstrate that our proposed policies have the potential to be a method of virus suppression, while at the same time allowing continued(albeit reduced) economic activity. Furthermore, these policies, while not eliminating the virus , can nevertheless be sustained over long periods of time, until a vaccine or treatment becomes available . The robustness of these policies stems from the fact that they are open loop methods; namely, lock-down periods are not triggered by measurements -- inevitably uncertain and delayed -- over short time scales such as hospital admissions, but rather are driven by predictable, high-frequency, periodic triggers in- and out- of lock-down. A slow and inherently robust outer supervisory feedback loop, based on measurements  over longer time scales , is used to tune the parameters of the mitigationstrategy. These methods can act alone, or can be used in combination with other mitigation strategies, to provide additional levels of effectiveness in their operation .
 COVID-19 abatement strategies have risks and uncertainties which could lead to repeating waves of infection. We show -- as proof of concept grounded on rigorous mathematical evidence -- that periodic, high-frequency alternation of into, and out-of, lockdown effectively mitigates second-wave effects, while allowing continued, albeit reduced , economic activity. Periodicity confers (i) predictability, which is essential for economic sustainability, and (ii) robustness, since lockdown periods are not activated by uncertain measurements over short time scales. In turn -- while not eliminating the virus -- this fast switching policy is sustainable over time, and it mitigates the infection until a vaccine or treatment becomes available , while alleviating the social costs associated with long lockdowns. Typically, the policy might be in the form of 1-day of work followed by 6-days of lockdown every week (or perhaps 2 days working, 5 days off) and it can be modified at a slow-rate based on measurements filtered over longer time scales . Our results highlight the potential efficacy of high frequency switching interventions in post lockdown mitigation. All code is available on Github URL A software tool has also been developed so that interested parties can explore the proof-of-concept system .
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Fast intermittent lock-down intervals with regular period are suggested as a
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exit strategy from the widely adopted policy of total lock-down. Many proposed exit
abatement
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a second wave of infection
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repeating waves of infection. We show -- as proof of concept grounded on rigorous mathematical evidence -- that periodic, high-frequency alternation of into, and out-of, lockdown effectively mitigates second-wave effects, while allowing continued, albeit reduced
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2
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. We demonstrate that our proposed policies have the potential to be a method of virus suppression, while at the same time allowing continued(albeit reduced)
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Furthermore, these policies,
Periodicity confers (i) predictability, which is essential for economic sustainability, and (ii) robustness, since lockdown periods are not activated by uncertain measurements over short time scales. In turn --
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, can nevertheless be sustained over long periods of time,
-- this fast switching policy is sustainable over time, and it mitigates the infection
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. The robustness of these policies stems from the fact that they are open loop methods; namely, lock-down periods are not triggered by measurements -- inevitably uncertain and delayed -- over short time scales such as hospital admissions, but rather are driven by predictable, high-frequency, periodic triggers in- and out- of lock-down. A slow and inherently robust outer supervisory feedback loop,
, while alleviating the social costs associated with long lockdowns. Typically, the policy might be in the form of 1-day of work followed by 6-days of lockdown every week (or perhaps 2 days working, 5 days off) and it can be modified at a slow-rate
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filtered
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, is used to tune the parameters of the mitigationstrategy. These methods can act alone, or can be used in combination with other mitigation strategies, to provide additional levels of effectiveness in their operation
. Our results highlight the potential efficacy of high frequency switching interventions in post lockdown mitigation. All code is available on Github URL A software tool has also been developed so that interested parties can explore the proof-of-concept system