Correcting social norm misperceptions to counter online vaccine misinformation during pandemics

Online vaccine misinformation circulating on social media undermines public health efforts, yet factual debunking alone has shown limited success in improving vaccination intentions. We tested whether combining descriptive social norm information with factual debunking improves the correction of online vaccine misinformation, alters its mechanism of influence, and varies in effectiveness by prior COVID-19 vaccination status. In an online experiment, 731 UK adults were randomly assigned to view online vaccine misinformation about a hypothetical pandemic (Covid-66) under one of three conditions: debunked combined with descriptive norm messaging, debunked alone, or not corrected at all.

Vaccine intentions and perceived peer vaccination norms were measured before and after exposure. Uncorrected online vaccine misinformation significantly reduced vaccine intentions by 2.7 percentage points (p