[1] St Georges Univ London, St Georges Hosp, Fetal Med Unit, London, England
[2] St Georges Univ London, Mol & Clin Sci Res Inst, Vasc Biol Res Ctr, London, England
[3] Royal Coll Obstetricians & Gynaecologists, London, England
[4] Karolinska Inst, Dept Womens & Childrens Hlth, S-17177 Stockholm, Sweden
[5] Karolinska Univ Hosp, Astrid Lindgren Childrens Hosp, Stockholm, Sweden
[6] Univ Oslo, Ctr Funct Tissue Reconstruct, FUTURE, Oslo, Norway
[7] UK Hlth Secur Agcy, Immunisat & Countermeasures Div, London, England
[8] St Georges Univ London, Paediat Infect Dis Res Grp, London, England
[9] St Georges Univ London, Vaccine Inst, Inst Infect & Immun, London, England