1. The Cochrane Collaboration; Vaccines Field; Via Adige 28a Anguillara Sabazia Roma Italy 00061
2. Health Reviews Ltd; Via Adige 28a Anguillara Sabazia Roma Italy 00061
3. Blue Cross Blue Shield of Rhode Island; Health and Wellness Division; 15 LaSalle Square Providence Rhode Island USA 02903
4. Institute for Healthcare Improvement; 143 Garden Street Wethersfield Hartford, CT 06109 USA