[1] Univ Milan, Fdn IRCCS Ca Granda Osped Maggiore Policlin, Pediat Highly Intens Care Unit, Milan, Italy
[2] Univ Florence, Dept Hlth Sci, Florence, Italy
[3] Aging Branch Ctr Res, CNR Inst Neurosci, Padua, Italy
[4] Immunizat Act Coalit, St Paul, MN USA
[5] Univ Genoa, IRCCS San Martino IST Univ Teaching Hosp, Dept Hlth Sci, Genoa, Italy
[6] Univ Bari, Unit Publ Hlth, Bari, Italy
[7] Soroka Univ, Med Ctr, Pediat Infect Dis Unit, Beer Sheva, Israel
[8] Ben Gurion Univ Negev, Fac Hlth Sci, Beer Sheva, Israel
[9] Univ Geneva, Geriatr Dept, Geneva, Switzerland
[10] Univ Antwerp, Vaccine & Infect Dis Inst, Antwerp, Belgium
[11] Dept Infect Dis, Annecy, France
[12] Charles Univ Prague, Fac Med, Dept Social Med, Hradec Kralove, Czech Republic
[13] Tampere Univ Hosp, Vaccine Res Ctr, Tampere, Finland
[14] Univ Modena & Reggio Emilia, Clin Infect Dis, Modena, Italy
[15] Heidelberg Univ, Dept Infect Dis, Div Infect Control & Hosp Epidemiol, Heidelberg, Germany
[16] Univ Vet Med Hannover, Hannover, Germany
[17] European Ctr Dis Control & Prevent, Stockholm, Sweden
[18] Univ Milan, Dept Clin Sci & Community Hlth, Milan, Italy
[19] Univ Hosp Grenoble, Univ Clin Geriatr Med, Grenoble, France
[20] GREPI Univ Grenoble Alpes, Grenoble, France