We are grateful for the essential work of a large number of public health experts, clinical microbiologists, practitioners and clinicians who have been involved in the investigations at national and regional level including all the professionals of the Canarian Health Service and the Balearic Islands Health Service. We acknowledge the work of ECDC data manager, particularly Zsolt Bartha, and country cooperation teams in rapidly establishing the online reporting system in TESSy by 26 January 2020. We thank also the efforts of Catalin Albu, Adrian Prodan, Skaidra Kurapkiene, Per Rolfhamre and Anca Dragnea. ECDC also thanks the Epidemic Intelligence team that provides vital and timely data on global cases of COVID-19. WHO thanks Ka Yeung (Calvin) Cheng, Silviu Ciobanu, Gudrun Freidl, Lauren MacDonald, and Miriam Sneiderman for assistance with data management.