A Study to Look at the Health Outcomes of Patients With COVID-19 and Influenza.

This is a prospective non-interventional longitudinal cohort survey study. Repeated measures on PROs: symptoms (prevalence, frequency, duration, and severity), EQ-5D-5L, WPAI and PROMIS-Fatigue short form 8a over 6 months will be collected and evaluated. COVID-19 Cohort: Participants 18 years or older with laboratory-confirmed COVID-19 illness and at least one patient-reported symptom. Influenza Cohort: Participants 18 years or older with laboratory-confirmed influenza illness and at least one patient-reported symptom. All study objectives and outcomes will be assessed separately for the two study cohorts.