The main purpose of this study is to understand: * the symptoms of COVID-19 or influenza- health-related outcomes of people with COVID-19 or influenza (influenza only included in updated study analyses) * the potential effects of COVID-19 vaccines in people with COVID-19 This study will enroll participants who are: * 18 years or older * reported to have symptoms with tests that have confirmed illness. The tests can be taken at any of CVS pharmacy COVID-19 or influenza test sites. The study will collect vaccine history information from participants who are ready to take part in the study. Participant will be emailed a form with questions about their health related to COVID-19 or influenza during multiple follow-ups over a 6-month period.