1 DIBIC Luigi Sacco, University of Milan, Milan, Italy stefano.rusconi@unimi.it.
2 Infectious Diseases Unit, Ospedale Civile di Legnano, Legnano, Italy.
3 School of Public Health, Southern Medical University, Guangzhou, China.
4 Institute of Global Health and Infectious Diseases, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA.
5 Faculty of Medicine, Fondazione PTV Policlinico Tor Vergata, Roma, Italy.
6 School of Immunology and Microbial Sciences, King's College London, London, UK.