[1] Univ Copenhagen, Dept Global Hlth, Copenhagen, Denmark
[2] Gentofte Univ Hosp, Dept Pediat, Gentofte, Denmark
[3] Skejby Univ Hosp, Dept Pediat, Aarhus, Denmark
[4] Hilleroed Hosp, Dept Pediat, Hillerod, Denmark
[5] Sanofi Pasteur MSD ApS, Lyngby, Denmark
[6] Viborg Hosp, Dept Pediat, Viborg, Denmark
[7] Univ Copenhagen Hosp, Pediat Clin 2, Rigshosp, DK-2100 Copenhagen, Denmark
[8] Holbaek Cent Hosp, Dept Pediat, Holbaek, Denmark
[9] Naestved Hosp, Dept Pediat, Naestved, Denmark
[10] Odense Univ Hosp, Hans Christian Andersen Childrens Hosp, DK-5000 Odense, Denmark
[11] Glostrup Cty Hosp, Dept Pediat, Glostrup, Denmark