1. South African Vaccination and Immunisation Centre, Department of Virology, Sefako Makgatho Health Sciences University
2. South African Medical Research Council/Sefako Makgatho Health Sciences University Diarrhoeal Pathogens Research Unit, Department of Virology, Sefako Makgatho Health Sciences University
3. Independent Consultant, Pretoria, South Africa
4. Network for Education and Support in Immunisation, Department of Epidemiology and Social Medicine, University of Antwerp, Antwerp, Belgium