1. Department of Laboratorio Inmuno-Biología Molecular, Hospital General Universitario Gregorio Marañón, Madrid, Spain
2. National Institute for Infectious Diseases IRCCS “L. Spallanzani”, Rome, Italy
3. Department of Pathology, Children’s Hospital Bambino Gesù, Rome, Italy
4. Department of Biology, University of Rome “Tor Vergata”, Rome, Italy