University of Melbourne - Department of General Medicine, University of Tasmania, University of Ibadan - Faculty of Public Health, Sacred Heart Hospital, Sacred Heart Hospital, University of Ibadan - Faculty of Public Health, Sacred Heart Hospital, University of Ibadan, Sacred Heart Hospital, University of Ibadan, University of Ibadan - University College Hospital, University of Melbourne - Department of General Medicine, University of Melbourne - Department of General Medicine, University of Melbourne - Department of Paediatrics, University College Hospital Ibadan, University of Melbourne - Department of General Medicine, University of Tasmania, University of Ibadan - Department of Paediatrics, Royal Hobart Hospital and University of Melbourne - Department of General Medicine

Aminu Kano Teaching Hospital, McKing Consulting Corporation, World Health Organization (WHO) - Polio Eradication Department, University of Maiduguri, Lagos University Teaching Hospital, University of Ibadan, Federal University Dutse, affiliation not provided to SSRN, affiliation not provided to SSRN, Aminu Kano Teaching Hospital, Government of the United States of America - Division of Viral Diseases, World Health Organization (WHO) - Polio Eradication Department, World Health Organization (WHO) - Polio Eradication Department and affiliation not provided to SSRN