[1] Univ Hosp & Med Ctr, Dept Med 2, Div Infect Dis, Freiburg, Germany
[2] Albert Ludwigs Univ, Fac Med, Freiburg, Germany
[3] Univ Freiburg, Fac Med, Inst Med Biometry & Stat, Freiburg, Germany
[4] Univ Freiburg, Med Ctr, Freiburg, Germany
[5] Univ Hosp & Med Ctr, Dept Environm Hlth Sci, Freiburg, Germany
[6] Univ Hosp & Med Ctr, Hosp Infect Control, Freiburg, Germany
[7] Albert Ludwigs Univ, Fac Med, Univ Hosp & Med Ctr, Div Hematol Oncol &Stem Cell Transplantat,Dept Me, Freiburg, Germany
[8] Charite Univ Med Ctr, Inst Hyg & Environm Med, Berlin, Germany
[9] Univ Hosp Basel, Div Infect Dis & Hosp Epidemiol, Basel, Switzerland
[10] Gesundheitsverbund Landkreis Konstanz, Hausherrenstr 12, D-78315 Radolfzell am Bodensee, Germany
[11] Pfizer Vaccines Med & Sci Affairs, 23-25 Ave Dr Lannelongue, F-75668 Paris 14, France