This observational study aims to monitor the side effects of COVID-19 vaccines worldwide actively.

The primary objectives of the project include a) to estimate the prevalence of each local and systemic side effect of each COVID-19 vaccine among healthcare workers (HCW), old adults over +65 (OA), and schoolteachers (ST); b) to evaluate the potential demographic and medical risk factors for side effects frequency and intensity; c) to evaluate the long-term consequences of COVID-19 vaccines.

The secondary objectives include a) to evaluate the relative safety of COVID-19 vaccines compared to each other; b) to evaluate the impact of palliative drugs used by the recently vaccinated individuals on their short-term side effects resolution.