[1] Univ Med Ctr Utrecht, Eijkman WInkler Inst, Dept Virol, Utrecht, Netherlands
[2] Wilhelmina Childrens Hosp, Dept Pediat Immunol, Utrecht, Netherlands
[3] Wilhelmina Childrens Hosp, Dept Pediat Infect Dis, Utrecht, Netherlands
[4] Wilhelmina Childrens Hosp, Dept Pediat Hematol, Utrecht, Netherlands