From infodemics to collective resistance: populist mobilisation and health consequences.

The COVID-19 pandemic unfolded alongside an unprecedented 'infodemic' that reshaped public engagement with science, health, and authority. This study examines how online infodemics translated into collective resistance and influenced population health through political mobilisation. Using structural equation models across six European countries, I conceptualise resistance as a latent construct - captured by residential mobility and protests opposing vaccines, lockdowns, and public health measures linked to populist radical right (PRR) movements - acting as a behavioural bridge between digital information environments and epidemic outcomes. The findings reveal a robust infodemic-resistance-epidemic pathway: greater exposure to infodemic content consistently predicts stronger opposition to non-pharmaceutical interventions (NPIs) and vaccination. This effect is strongest in Germany and Italy, where PRR networks amplified narratives of 'elite overreach' and 'freedom under threat', transforming online discontent into organised mobilisation. In other countries, resistance appears weaker and more pandemic-specific. By integrating informational, political, and epidemiological processes, the analysis shows how epidemics can evolve into politicised collective behaviour that undermines compliance and sustains transmission. The results highlight populist mobilisation as a key amplifier of epidemic risk and suggest that effective responses must rebuild trust, depoliticise health communication, and address structural sources of grievance.