Trust, ideology, and vaccine conspiracy beliefs during the COVID-19 pandemic in Spain

Conspiracy theories about COVID-19 vaccines – ranging from alleged hidden dangers to claims of pharmaceutical manipulation – spread widely during the pandemic, undermining vaccination efforts. This study examines whether ideological orientation and trust in scientific authorities were associated with such beliefs in Spain during 2021. Drawing on three nationally representative survey rounds (N = 6,308), the analysis shows that right-wing self-placement became increasingly associated with vaccine-related conspiracy beliefs over the year, while trust in scientific authorities was consistently and negatively related to them. These findings indicate that ideological orientation and declining confidence in expertise were linked to the persistence of conspiracy thinking in Spain during the COVID-19 pandemic. The study shows how political polarisation and trust in expertise shape public responses to health crises over time.