[1] Fdn Polyclin Tor Vergata, Mol Virol Lab, I-00133 Rome, Italy
[2] Ist Super Sanita, Dept Infect Parasit & Immunomediated Dis, I-00161 Rome, Italy
[3] Univ Tor Vergata, Dept Expt Med & Biochem Sci, Rome, Italy
[4] Jaslok Hosp & Res Ctr, Bombay, Maharashtra, India