A large outbreak of COVID-19 linked to an end of term trip to Menorca (Spain) by secondary school students in summer 2021.

Background: An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurred in young people from Catalonia (Spain) who travelled to Menorca (Spain) in summer 2021. This outbreak appeared when governments relaxed Covid-19 preventive measures: the mask usage and the opening of nightlife. It was related to a super-disseminating mass event: Sant Joan festivities in Ciutadella.