The GCoVS project, led by Global Vaccine Data Network (GVDN) and supported by funding from the U.S. Centers for Disease Control and Prevention (CDC), aims to evaluate the safety of COVID-19 vaccines across diverse and extensive study populations, leveraging the participation of 26 countries within the GVDN consortium. VAC4EU serves as the coordinating centre for European sites. The project’s objective is to contribute to the investigation of the potential association between COVID-19 vaccines and selected adverse reactions, and any underlying genetic predispositions to these reactions. VAC4EU is involved in several studies within this project, including an Association Study and a Genomic Study.