Background
Videos have been an important medium for providing health and risk communication to the public during the COVID-19 pandemic [The modified Integrated-Change Model [This study addresses the research gap regarding the effect of nonvisual information factors on communication outcomes. The aim of the study is to assess the effect of 3 aspects of the messenger (source) and the message (topic and call to action) on the outcomes (trust, comprehension, intentions, and behavior) of pandemic video communication. Therefore, the source, topic, and call to action are the independent variables, whereas trust, comprehension, intentions, and behavior are the dependent variables of our study. The rationale for the choice of variables is described in the following paragraphs.