Speaker
Description
Peer influence can act as an invisible force that promotes or hinders the adoption of health-protective behaviours. While traditional epidemiological models focus on physical contacts driving transmission, they often overlook the social interactions through which opinions and behaviours spread.
We use contact data from a multinational survey of over 22,000 respondents across six European countries to construct age-stratified matrices for disease transmission and social contagion \cite{offeddu2025advancing}, distinguishing physical from discussion-based interactions. We develop a stochastic SIR model in which adoption and abandonment of protective behaviours are mediated by discussion contacts and modulated by infection and recovery levels through non-linear responses.
Incorporating empirical discussion mixing into the model produces an earlier and sharper epidemic peak due to rapid behavioural uptake, followed by heterogeneous relaxation across age groups that generates a secondary wave absent under fixed adoption. Assuming the age structure of physical contacts for discussion yields epidemic trajectories that generally diverge from the empirical case, with more pronounced effects in some countries than others.
This data-driven framework captures peer-mediated behavioural contagion and shows how age-specific social influence can reshape both adoption and epidemic dynamics, underscoring its importance in fostering the uptake of protective behaviours.
Bibliography
@article{offeddu2025advancing,
title={Advancing coupled behavioural-epidemic models: An interdisciplinary framework for the collection of empirical data},
author={Offeddu, Vittoria and Colosi, Elisabetta and Lucchini, Lorenzo and Leone, Laura Pasqua and Chiavenna, Chiara and Balsamo, Duilio and D’Agnese, Elena and Bonacina, Francesco and Cucciniello, Maria and Trentini, Filippo and others},
journal={medRxiv},
pages={2025--10},
year={2025},
publisher={Cold Spring Harbor Laboratory Press}
}
