[1] Univ Childrens Hosp, Div Pediat Infect Dis & Vaccines, CH-4005 Basel, Switzerland
[2] Ctr Dis Control & Prevent, Atlanta, GA USA
[3] WHO, CH-1211 Geneva, Switzerland
[4] Swedish Inst Infect Dis Control, Stockholm, Sweden
[5] Cochrane Vaccines Field & Hlth Reviews Ltd, Rome, Italy
[6] Aventis Pasteur SA, Lyon, France