Messaging applications are changing the communication landscape in emergingcountries. While offering speed and affordability, these solutions have alsoopened the way for the spread of misinformation. Aiming to better understand thedynamics of COVID-19 as infodemic, we asked Brazilian participants (n=1007) toreport the perceived accuracy of 20 messages (10 true and 10 false). Eachmessage was randomly presented within five fictitious WhatsApp group chats ofvarying political orientation. Correlational analyses revealed that right-wingparticipants had lower levels of truth discernment as did those with greatertrust in social media as a reliable source of coronavirus information.Conversely, open-minded thinking about evidence and trust in the WHO andtraditional media was positively associated with truth discernment. Familiaritywith the content consistently increased perceived truthness for both true andfalse messages. Results point to the nefarious effects of COVID-19politicization and underline the importance of promoting the ability torecognize and value new evidence as well as enhancing trust in internationalagencies and traditional media.