The influence of COVID-19 risk perception and vaccination status on the number of social contacts across Europe: insights from the CoMix study

Abstract

Background The SARS-CoV-2 transmission dynamics have been greatly modulated by human contact behaviour. To curb the spread of the virus, global efforts focused on implementing both Non-Pharmaceutical Interventions (NPIs) and pharmaceutical interventions such as vaccination. This study was conducted to explore the influence of COVID-19 vaccination status and risk perceptions related to SARS-CoV-2 on the number of social contacts of individuals in 16 European countries. Methods We used data from longitudinal surveys conducted in the 16 European countries to measure social contact behaviour in the course of the pandemic. The data consisted of representative panels of participants in terms of gender, age and region of residence in each country. The surveys were conducted in several rounds between December 2020 and September 2021 and comprised of 29,292 participants providing a total of 111,103 completed surveys. We employed a multilevel generalized linear mixed effects model to explore the influence of risk perceptions and COVID-19 vaccination status on the number of social contacts of individuals. Results The results indicated that perceived severity played a significant role in social contact behaviour during the pandemic after controlling for other variables (p-value < 0.001). More specifically, participants who had low or neutral levels of perceived severity reported 1.25 (95% Confidence intervals (CI) 1.13 - 1.37) and 1.10 (95% CI 1.00 - 1.21) times more contacts compared to those who perceived COVID-19 to be a serious illness, respectively. Additionally, vaccination status was also a significant predictor of contacts (p-value < 0.001), with vaccinated individuals reporting 1.31 (95% CI 1.23 - 1.39) times higher number of contacts than the non-vaccinated. Furthermore, individual-level factors played a more substantial role in influencing contact behaviour than country-level factors. Conclusion Our multi-country study yields significant insights on the importance of risk perceptions and vaccination in behavioral changes during a pandemic emergency. The apparent increase in social contact behaviour following vaccination would require urgent intervention in the event of emergence of an immune escaping variant.

Host behaviour driven by awareness of infection risk amplifies the chance of superspreading events

“…This constraint causes some event sizes to have importation rates above and others below ρ and allows us to model a spectrum of risk appetites about the baseline prevalence. This variability in risk perception aligns well with trends found in behavioural surveys [12–14].…”

“…To avoid all of the above issues, we only considered initial epidemic stages and focussed on isolating the risk-awareness induced patterns given a set of events and a prevalence baseline. We made a minimal assumption, supported by survey data on population behaviours [12–14], that there is a spectrum of risk about this baseline. Our aim was twofold – to discover how risk perceptions could impact superspreading and to show why collecting auxiliary data describing variations in epidemic-related human behaviour, such as event attendance, are necessary.…”

“…Despite its importance, the interplay between risk awareness and superspreading risk has not been studied in detail, with most research focussing on pathogen and host characteristics instead of exploring behavioural patterns. We study this interplay under a simple but plausible hypothesis – that more risk-averse hosts are more likely to avoid events of larger size, due to the perception of heightened infection risk at those events [14,19]. Here, events are short-term gatherings (e.g., parties) so that only one generation of infection is possible.…”

“…Risk awareness is a documented phenomenon in which individuals engage in self-protective behaviours in response to the perceived health, economic and other dangers of acquiring infection. The exact relationship between risk-perception and self-protection in a population exists on a spectrum spanning more risk-averse individuals to those with larger risk appetites (e.g., risk deniers) [12][13][14]. During an epidemic of a directly transmitted pathogen, risk-averse individuals may reduce their number of contacts by limiting their socialising and mobility, while those with larger risk appetites may increase their relative infection exposure (e.g., by hosting unregulated gatherings when infections are rising) [15].…”

Repetition in Social Contact Interactions: Implications in Modelling the Transmission of Respiratory Infectious Diseases in Pre-pandemic & Pandemic Settings

“…Numerous studies similar in setup have been conducted in different countries in both pre-pandemic and pandemic periods [4]. The CoMix study is the largest study across Europe gathering social contact data aiming to assess changes in contact behaviour during the pandemic [2,6–11]. The information from these surveys has proven invaluable in informing transmission dynamics within mathematical models including network models [12], agent-based models [13], and compartmental models [14–16].…”