Athina Samara a, b, c, Conrado Milani Coutinho d, Philip Veal e, Jane Osborne f, Geraldo Duarte d, Shamez Ladhani g, h, i, Asma Khalil j, k, l 
a Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden
b Astrid Lindgren Children’s Hospital, Karolinska University Hospital, Stockholm, Sweden
c FUTURE, Center for Functional Tissue Reconstruction, University of Oslo, Oslo, Norway
d Hospital das Clínicas, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
e Travel Health and International Health Regulations Team, UK Health Security Agency, London, UK
f Rare and Imported Pathogens Laboratory, UK Health Security Agency, London, UK
g Immunisation and Countermeasures Division, UK Health Security Agency, London, UK
h Paediatric Infectious Diseases Research Group and Vaccine Institute, Institute of Infection and Immunity, St George’s University of London, London, UK
i British Paediatric Surveillance Unit, Royal College of Paediatrics and Child Health, London, UK
j Fetal Medicine Unit, St George’s University Hospitals NHS Foundation Trust, University of London, London SW17 0QT, UK
k Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute, St George’s University of London, London, UK
l Royal College of Obstetricians and Gynaecologists, London, UK