1 Microbiology and Virology Unit, S. Maria delle Scotte University Hospital of Siena, Siena, Italy; Virology Unit, Department of Medical Biotechnologies, University of Siena,V.le Bracci, 1, Siena, 53100, Italy. Electronic address: claudia.gandolfo@unisi.it.
2 Department of Experimental and Clinical Medicine, University of Florence, and Clinical Microbiology and Virology Unit, Careggi University Hospital, Florence, Italy. Electronic address: fabio.morecchiato@unifi.it.
3 Department of Translational Medicine and New Technologies in Medicine and Surgery, Retrovirus Centre, University of Pisa, Italy. Electronic address: mauro.pistello@unipi.it.
4 Department of Experimental and Clinical Medicine, University of Florence, and Clinical Microbiology and Virology Unit, Careggi University Hospital, Florence, Italy. Electronic address: gianmaria.rossolini@unifi.it.
5 Microbiology and Virology Unit, S. Maria delle Scotte University Hospital of Siena, Siena, Italy; Virology Unit, Department of Medical Biotechnologies, University of Siena,V.le Bracci, 1, Siena, 53100, Italy. Electronic address: mariagrazia.cusi@unisi.it.