Question-explanation exchanges in parent-child interactions foster children's early learning, especially when children are inquiring about unobservable scientific phenomena such as the novel coronavirus (COVID-19). As with other unobservable entities, children must rely on adults to acquire knowledge about COVID-19. Yet, we know very little about what children understand about COVID-19 or its consequences. In our study, we explored developmental changes in children's questions about COVID-19 and parents' explanations. Parents (n = 182) of children (aged 3-8) completed an online survey, which included demographic information, parents' explanations, and children's questions. Parents' explanations "referenced germs," used "illness analogies," and mentioned "mitigation strategies." Most of children's COVID-related questions focused on the "consequences of COVID-19." Whereas older children asked more about "death," younger children asked about loss of "activities." The findings advance our understanding of the impact of COVID-19 on parents and children.