Social behaviours and contact patterns across the 2020/21, 2021/22 and 2022/23 winter seasons in the UK, and associations with symptoms

The SARS-CoV-2 pandemic had a large impact on social mixing in the UK. This study analysed data from the Office for National Statistics Coronavirus Infection Survey to examine changes in contact patterns and self-reported symptoms through three winter seasons from 2020 to 2023. Using Generalised Additive Models, we estimated levels of various contacts over time, accounting for age, sex, ethnicity, and deprivation percentile, and compared these to trends in self-reported symptoms. Our estimates indicated steady increases in physical contacts from quarter-4 2020 to the end of the study in quarter-1 2023, with notable variation in age-specific trends. School closures and holiday periods had substantial impacts on contact patterns, particularly for children. Prevalence of reported symptoms also increased steadily over time, but varied much more within-season than most contacts; specifically, the relative increase in respiratory symptom prevalence during winter peaks between seasons was much larger than increases in contacts. Our estimates also suggested that while age played a crucial role in both contact patterns and symptom reporting, the effects of deprivation were less clear and far smaller. Our findings provide insights into changes in behaviours and symptoms during the pandemic, which may help inform future public health policy and infection modelling.