[1] Hlth Protect Agcy NE, NE Hlth Protect Unit, Newcastle Upon Tyne NE1 4WH, Tyne & Wear, England
[2] S Tees Hosp NHS Fdn Trust, Dept Paediat, Middlesbrough, Cleveland, England
[3] Hlth Protect Agcy, Vaccine Evaluat Unit, Manchester, Lancs, England
[4] Hlth Protect Agcy, Meningococcal Reference Unit, Manchester, Lancs, England
[5] S Tees Hosp NHS Fdn Trust, Dept Clin Microbiol, Middlesbrough, Cleveland, England
[6] Hlth Protect Agcy, Hlth Protect Serv Colindale, London, England
[7] Newcastle Upopn Tyne Hosp NHS Fdn Trust, Dept Paediat Immunol & Infect Dis, Newcastle Upon Tyne, Tyne & Wear, England