[1] Univ Tubingen, NMI Nat & Med Sci Inst, Reutlingen, Germany
[2] Helmholtz Ctr Infect Res, Dept Epidemiol, Braunschweig, Germany
[3] German Ctr Infect Res DZIF, TI BBD, Partner Site Hannover Braunschweig, Braunschweig, Germany
[4] Imperial Coll London, Dept Infect Dis, London, England
[5] Univ Childrens Hosp, Dept Pediat Neurol & Dev Med, Tubingen, Germany
[6] Univ Hosp Tubingen, Inst Med Virol & Epidemiol Viral Dis, Tubingen, Germany