1. The Cochrane Collaboration; Vaccines Field; Via Adige 28a Anguillara Sabazia Roma Italy 00061
2. Azienda Sanitaria Locale ASL AL; Servizio Regionale di Riferimento per l'Epidemiologia, SSEpi-SeREMI - Cochrane Vaccines Field; Via Venezia 6 Alessandria Piemonte Italy 15100
3. College of Medicine, King Saud University; Department of Family & Community Medicine, Holder of "Shaikh Abdullah S. Bahamdan" Research Chair for Evidence-Based Health Care and Knowledge Translation; P.O.Box 2925 Riyadh Saudi Arabia 11461
4. Public Health Agency of Lazio Region; Infectious Diseases Unit; Via di Santa Costanza, 53 Rome Italy 00198
5. Bond University; Faculty of Health Sciences and Medicine; Gold Coast Queensland Australia 4229
6. University of Calgary; Department of Medicine; UCMC #1707-1632 14th Avenue Calgary Alberta Canada T2M 1N7