Social contact patterns following the COVID-19 pandemic: a snapshot of post-pandemic behaviour from the CoMix study
Christopher I. Jarvis,
Pietro Coletti,
Jantien A. Backer,
James D. Munday,
Christel Faes,
Philippe Beutels,
Christian L. Althaus,
Nicola Low,
Jacco Wallinga,
Niel Hens,
W.John Edmunds
Affiliations
Christopher I. Jarvis
Centre for Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
Pietro Coletti
Data Science Institute, I-Biostat, Hasselt University, Agoralaan Gebouw D, Diepenbeek 3590, Belgium; Corresponding author:.
Jantien A. Backer
Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, the Netherlands
James D. Munday
Centre for Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; Department of Biosystems Science and Engineering, ETH Zürich, Switzerland
Christel Faes
Data Science Institute, I-Biostat, Hasselt University, Agoralaan Gebouw D, Diepenbeek 3590, Belgium
Philippe Beutels
Data Science Institute, I-Biostat, Hasselt University, Agoralaan Gebouw D, Diepenbeek 3590, Belgium; Centre for Health Economics Research and Modelling Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Universiteitsplein 1, Wilrijk 2610, Belgium
Christian L. Althaus
Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
Nicola Low
Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
Jacco Wallinga
Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, the Netherlands; Department of Biomedical Data Sciences, Leiden University Medical Center, Leiden, the Netherlands
Niel Hens
Data Science Institute, I-Biostat, Hasselt University, Agoralaan Gebouw D, Diepenbeek 3590, Belgium; Centre for Health Economics Research and Modelling Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Universiteitsplein 1, Wilrijk 2610, Belgium
W.John Edmunds
Centre for Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
The COVID-19 pandemic led to unprecedented changes in behaviour. To estimate if these persisted, a final round of the CoMix social contact survey was conducted in four countries at a time when all societal restrictions had been lifted for several months. We conducted a survey on a nationally representative sample in the UK, Netherlands (NL), Belgium (BE), and Switzerland (CH). Participants were asked about their contacts and behaviours on the previous day. We calculated contact matrices and compared the contact levels to a pre-pandemic baseline to estimate R0. Data collection occurred from 17 November to 7 December 2022. 7477 participants were recruited. Some were asked to undertake the survey on behalf of their children. Only 14.4 % of all participants reported wearing a facemask on the previous day. Self-reported vaccination rates in adults were similar for each country at around 86 %. Trimmed mean recorded contacts were highest in NL with 9.9 (95 % confidence interval [CI] 9.0–10.8) contacts per person per day and lowest in CH at 6.0 (95 % CI 5.4–6.6). Contacts at work were lowest in the UK (1.4 contacts per person per day) and highest in NL at 2.8 contacts per person per day. Other contacts were also lower in the UK at 1.6 per person per day (95 % CI 1.4–1.9) and highest in NL at 3.4 recorded per person per day (95 % CI 43.0–4.0). The next-generation approach suggests that R0 for a close-contact disease would be roughly half pre-pandemic levels in the UK, 80 % in NL and intermediate in the other two countries. The pandemic appears to have resulted in lasting changes in contact patterns expected to have an impact on the epidemiology of many different pathogens. Further post-pandemic surveys are necessary to confirm this finding.
