This study examines how age and exposure to different types of COVID-19 (mis)information affect misinformation beliefs, perceived credibility of the message, and intention-to-share it on WhatsApp. Two mixed-design online experiments in the UK and Brazil (N=1454) exposed adult WhatsApp users to full misinformation, partial misinformation, or full truth about garlic's therapeutic powers to cure COVID-19, followed by corrective information from the WHO. Younger adults (18–54) showed stronger misinformation beliefs in both countries. Older adults (55+) in the UK exhibited potential backfire effects from corrective information. WHO corrective information effectively enhanced perceived credibility and intention-to-share accurate information across all groups. The findings highlight the need for evidence-based infodemic interventions targeting younger adults.

Santosh Vijaykumar, Yan Jin, Daniel Rogerson, Xuerong Lu, Swati Sharma, Anna Maughan, Bianca Fadel, Mariella Silva de Oliveira Costa, Claudia Pagliari, Daniel Morris