1. Pediatric Unit, Hospital of Trento, Trento, Italy
2. Epidemiology Department, Sanofi Pasteur MSD, Lyon, France
3. International Pharmacoepidemiology and Pharmacoeconomics Research Center, Desio, Italy
4. Division of Pediatric Infectious Diseases, Department for Woman and Child Health, University of Padova, Padova, Italy
5. Epidemiology Service, Local Health Authority of Cremona, Cremona, Italy
6. Family Pediatrician, Pedianet Project, Padova, Italy