In this project, we will evaluate the use and performance of a CE-marked device (wearable), which uses sensors to measure breathing rate, pulse rate, skin temperature, and heart rate variability for the purpose of early detection and monitoring of COVID-19 in general and high-risk populations. At the same time, a mobile application will be used to track participant-reported symptoms. A prospective, observational study will follow 13,000 individuals from the general population and 7,000 high-risk individuals wearing the device and responding to participant self-report parameters via a purpose-designed app. Based on this data, an algorithm will indicate which individuals likely require general practitioner (GP) care (for COVID-19 diagnostic testing, further vital signs assessment, and/or treatment) and/or hospital care. To evaluate algorithm performance, the cohort will be tested for COVID-19 antibodies at the end of follow-up. COVID-19 seropositivity in the intervention cohort will be compared seropositivity in a control population of 20,000 individuals drawn from the same populations using the application only. Thus, this project will deliver a large body of information on COVID-19 PCR testing and antibodies that can be used to develop additional diagnostics and therapeutics in addition to validating remote vital signs and self-reported symptoms monitoring systems.