Social Contact Patterns and Age Mixing before and during COVID-19 Pandemic, Greece, January 2020–October 2021

Abstract

We collected social contact data in Greece to measure contact patterns before (January 2020) and during the COVID-19 pandemic (March 2020–October 2021) and assess the effects of social distancing over time. During lockdowns, mean daily contacts decreased to 2.8–5.9 (mean prepandemic 20.4). Persons >65 years of age retained the fewest contacts during the pandemic (2.1–4.1). Compared with the first lockdown (March–April 2020), the second lockdown (November–December 2020) and third lockdown (April 2021) showed higher numbers of contacts (incidence rate ratio 1.50 [95% CI 1.27–1.76] in second lockdown and 2.19 [95% CI 1.86–2.58] in third lockdown). In 2021, an increase in contacts was apparent, which persisted during the April 2021 lockdown among persons 18–64 years of age. Our study provides evidence of the waning observance of physical distancing. Effective risk communication alongside targeted social distancing could offer alternatives to repeated lockdowns.

Keywords

• COVID-19
• pandemic
• coronavirus disease
• SARS-CoV-2
• severe acute respiratory syndrome coronavirus 2
• viruses