The 2019 novel coronavirus (COVID-19) has posed substantial threats to global public health. Individuals are extensively exposed to interpersonal sources of health information (e.g., family, friends, colleagues, physicians, and pharmacists). Interpersonal connections often encourage people to question or reinforce other sources of health information, which can affect their perceptions and behaviors. This study integrates research on how exposure to interpersonal health communication affects people's risk perception and affective responses to influence health-protective behaviors such as health information seeking and adherence to protective measures. Findings from an online survey of U.S. adults (n = 488) demonstrated that risk perception and affective responses serve as behavioral motivation factors. The influences of cognitive and affective responses were greater to the extent that individuals believed the health-protective behaviors are beneficial. Our study illuminates how people engage in preventive health behaviors to protect themselves in the COVID-19 context and demonstrates the influence of interpersonal social networks in motivating such behaviors. The theoretical and practical implications of these findings are discussed.