Low levels of respiratory syncytial virus activity in Europe during the 2020/21 season: what can we expect in the coming summer and autumn/winter? by van Summeren, J, Meijer, A, Aspelund, G, Casalegno, JS, Erna, G, Hoang, U, Lina, B, de Lusignan, S, Teirlinck, AC, Thors, V, Paget, J