The text considers several critical issues related to the role of false information in the COVID-19 pandemic. It mainly focuses on social media, which often resemble echo chambers responsible for disseminating disinformation. In these echo chambers, users close themselves off from arguments and justifications different from their own, often with a strong tendency towards polarization of views and attitudes. A particular case of echo chambers is the conspiracy mentality propagated in social media, promoting conspirational beliefs about COVID-19, which, besides offering an alternative understanding of reality, deepens distrust towards epistemic authorities and methods of producing scientific knowledge. This indicates an epistemic crisis as a consequence of the pandemic, which must be addressed in order to rebuild and protect epistemic trust. The authors conclude that the consequence of this crisis is a regression of cognitive abilities, which may, in a feedback loop, exacerbate the epistemic crisis.