Economic burden and health-related quality-of-life among infants with respiratory syncytial virus infection: a multi-country prospective cohort study in Europe by Mao, Z, Li, X, Dacosta-Urbieta, A, Billard, M-N, Wildenbeest, J, Korsten, K, Martinón-Torres, F, Heikkinen, T, Cunningham, S, Snape, MD, Robinson, H, Pollard, AJ, Postma, M, Dervaux, B, Hens, N, Bont, L, Bilcke, J, Beutels, P