Affiliation: | Author affiliations: University of Bologna, Bologna, Italy (G. Rossini, F. Cavrini, P. Gaibani, M.P. Landini, A. Pierro, V. Sambri);;National Institute for Infectious Diseases “L. Spallanzani,” Rome, Italy (F. Carletti, L. Bordi, M.R. Capobianchi, A. Di Caro) |