1 Laboratory of Virology, National Institute for Infectious Diseases L. Spallanzani, Istituto Di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome.
2 Department of Microbiology, Section of the Department of Experimental, Diagnostic and Specialty Medicine, School of Medicine, University of Bologna, Bologna.
3 Laboratory of Virology, National Institute for Infectious Diseases L. Spallanzani, IRCCS, Rome, Italy. claudia.caglioti@inmi.it.