 This study analyzed Italian web pages mentioning squalene-based adjuvants in influenza vaccines and found that a high prevalence, 47.6% of pages had negative or ambiguous attitudes towards these adjuvants, which were associated with lower odds of belonging to professional institutions and higher odds of containing pictures and being more readable, the most common scientifically unsound claims concern safety issues and Gulf War syndrome linkages. Institutional websites should provide evidence-based information carefully targeted towards laypeople, while non-institutional authors should avoid sensationalism and provide balanced information. This article was authored by Donatella Pannato, Daniela Amicizia, Lucia Areta, and others.