[1] Immunisat Div, UK Hlth Secur Agcy, London NW9 5EQ, England
[2] UK Hlth Secur Agcy, Modelling & Econ Unit, London, England
[3] UK Hlth Secur Agcy, Stat Modelling & Econ Dept, London, England
[4] UK Hlth Secur Agcy, Blood Safety Hepatitis STI & HIV Div, London, England
[5] St Georges Univ London, Ctr Neonatal & Paediat Infect, London, England
[6] Imperial Coll Sch Publ Hlth, MRC Ctr Global Infect Dis Anal, London, England
[7] Manchester Royal Infirm, UK Hlth Secur Agcy, Meningococcal Reference Unit, Manchester, England