We would like to gratefully acknowledge the support and data provided by WHO Regional Office for Europe colleagues in the WHO Health Emergencies Programme and Public Health and Social Measures (PHSM) team: Tanja Schmidt, Haris Hajrulahovic, Christoph Wippel, Esther Gonzalez, Sandra Lindstrom, Kayla King, Sara Barragan, Jennifer Addo, William van Grinsen, Katherine Smallwood and Dorit Nitzan.