Impact of national and regional lockdowns on COVID-19 epidemic waves: Application to the 2020 spring wave in France

Jonathan Roux (1, 2) , Clément Massonnaud (1, 2, 3) , Vittoria Colizza (4) , Simon Cauchemez (5) , Pascal Crepey (1, 2)

1 EHESP - École des Hautes Études en Santé Publique [EHESP]
2 REPERES - Recherche en Pharmaco-épidémiologie et Recours aux Soins
3 CHU Caen
4 iPLESP - Institut Pierre Louis d'Epidémiologie et de Santé Publique
5 Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases

Abstract Several countries have implemented lockdowns to control their COVID-19 epidemic. However, questions like “where” and “when” still require answers. We assessed the impact of national and regional lockdowns considering the French first epidemic wave of COVID-19 as a case study. In a regional lockdown scenario aimed at preventing intensive care units (ICU) saturation, almost all French regions would have had to implement a lockdown within 10 days and 96% of ICU capacities would have been used. For slowly growing epidemics, with a lower reproduction number, the expected delays between regional lockdowns increases. However, the public health costs associated with these delays tend to grow exponentially with time. In a quickly growing pandemic wave, defining the timing of lockdowns at a regional rather than national level delays by a few days the implementation of a nationwide lockdown but leads to substantially higher morbidity, mortality and stress on the healthcare system.

Mots clés: Impact; Lockdown; COVID-19; France

Domaines: Santé publique et épidémiologie

Jonathan Roux, Clément Massonnaud, Vittoria Colizza, Simon Cauchemez, Pascal Crepey. Impact of national and regional lockdowns on COVID-19 epidemic waves: Application to the 2020 spring wave in France. 2021. ⟨hal-03820475⟩