Relational agents (RAs) have shown effectiveness in various health interventions with and without healthcare professionals (HCPs) and hospital facilities. RAs have not been widely researched in COVID-19 context, although they can give health interventions during the pandemic. Addressing this gap, this work presents an early usability evaluation of a prototypical RA, which is iteratively designed and developed in collaboration with infected patients (n=21) and two groups of HCPs (n=19, n=16) to aid COVID-19 patients at various stages about four main tasks: testing guidance, support during self-isolation, handling emergency situations, and promoting post-infection mental well-being. The prototype obtained an average score of 58.82 on the system usability scale (SUS) after being evaluated by 98 people. This result implies that the suggested design still needs to be improved for greater usability and adoption.