Burden of respiratory syncytial virus infection in community-dwelling older adults in Europe (RESCEU): an international prospective cohort study by Korsten, K, Adriaenssens, N, Coenen, S, Butler, C, Ravanfar, B, Rutter, H, Allen, J, Falsey, A, Pirçon, J-Y, Gruselle, O, Pavot, V, Vernhes, C, Balla-Jhagjhoorsingh, S, Öner, D, Ispas, G, Aerssens, J, Shinde, V, Verheij, T, Bont, L, Wildenbeest, J, Pollard, AJ