Affiliation: | 1. Directorate of Research, Studies, and Documentation, National Public Health Organization, Athens, Greece;2. Department of Epidemiology, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia;3. Center for Disease Control and Prevention, Institute of Public Health of Vojvodina, Novi Sad, Serbia;4. Pediatric Department, Democritus University of Thrace, Alexandroupolis, Greece;5. Mayo Vaccine Research Group, Mayo Clinic and Foundation, Rochester, MN, United States |