1. National Centre for Disease Prevention and Health Promotion, Istituto Superiore di Sanità, 00161 Rome, Italy
2. National Centre for Global Health, Istituto Superiore di Sanità, 00161 Rome, Italy
3. Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
4. Department of Public Health and Infectious Diseases, Sapienza Università di Roma, 00185 Rome, Italy