Key Points

• After the first case of COVID-19 was identified in the region on February 27, 2020, three successive waves of the epidemic were observed between March 2020 and May 2021.

• The first wave (March to June 2020) had a significant impact on public health, though this was mitigated by the early implementation of a first lockdown.

• On July 15, 2020, Mayenne became the first metropolitan department classified as having high vulnerability to SARS-CoV-2 viral circulation, linked to multiple clusters—particularly in slaughterhouses—that led to community spread. Following the implementation of management measures by the Pays de la Loire Regional Health Agency (ARS), viral circulation returned to the regional average during the second wave of the pandemic.

• The second wave of the epidemic (August to late December 2020), which was particularly severe, disproportionately affected elderly residents in nursing homes.

• The third wave (January to May 2021), which was more widespread, was the most significant in terms of viral circulation and impact on the hospital system, likely linked to the circulation of the Alpha variant in the region.

• The number of reported clusters followed roughly the same trend as the regional incidence rate, primarily affecting workplaces, nursing homes, and schools and universities.

• Among the oldest adults, an improvement in COVID-19 epidemiological indicators was observed starting in February 2021 following the rollout of vaccination in this population at risk of severe disease.

• COVID-19 patients hospitalized in intensive care units had a median age of 66 and predominantly had comorbidities.

• Excess all-cause mortality was estimated for each of the three periods in the region, though it remained lower than the rates observed at the national level. It should be noted that the electronic death certification system, which provides information on causes of death, is not fully comprehensive in the region.

• The Pays de la Loire region, like the other regions along the Atlantic coast, was among the regions of France least affected by the COVID-19 epidemic during these three successive waves, though with varying dynamics across departments and a significant impact on healthcare provision, which led to major management and prevention efforts by public authorities and healthcare system stakeholders.