Lockdowns Should Last at Least 60 Days – But Could Be Avoided Entirely

• Lockdowns should remain in place for at least 60 days in order to avoid a second wave of cases.
• Gradual deconfinement strategies result in fewer cases and deaths than sudden release of a large proportion of the population.
• Social distancing and individual protection such as masks have a massive impact on the number of active cases, and can potentially remove the need for lockdowns.

While many countries have made it past their initial peak in cases, COVID-19 infections continue to rise elsewhere. Our ability to keep people with severe COVID-19 alive has increased, but we still don’t have an antiviral drug or vaccine, and probably won’t for quite some time. That means that currently, limiting the spread of the virus through social distancing and precautions such as mask wearing is the only way of bringing case numbers down.

Countries that introduced robust social distancing measures, particularly those that responded rapidly to the spread of the virus, have succeeded in bringing case numbers under control. Many of these countries and have subsequently relaxed restrictions or are considering doing so. However, the 1918 influenza pandemic had a deadly second wave of infections, a scenario that could be repeated with COVID-19, and there is some uncertainty over how this is to be best avoided.

This study uses modelling to predict how case numbers will change under different scenarios, such as varying duration of lockdown, relaxation strategies and social distancing practices:

Our results suggest that lockdowns should remain in place for at least 60 days to prevent epidemic growth, as well as a potentially larger second wave of SARS-CoV-2 cases occurring within months. The best-case scenario should also gradually incorporate workers in a daily proportion at most 50% higher than during the confinement period. We show that decaying immunity and particularly awareness and behaviour have 99% significant effects on both the current wave of infection and on preventing COVID-19 re-emergence. Social distancing and individual non-pharmaceutical interventions could potentially remove the need for lockdowns.

López, L., & Rodó, X. (2020). The end of social confinement and COVID-19 re-emergence risk. Nature Human Behaviour. doi: 10.1038/s41562-020-0908-8