1. Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
2. Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, USA
3. Division of Infectious Diseases, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA
4. Department of Medicine, Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, USA
5. Departments of Epidemiology & Biostatistics and Pediatrics & Human Development, Michigan State University, East Lansing, MI, USA
6. North-Western Tuscany Blood Bank, Pisa University Hospital, Pisa, Italy