affiliation not provided to SSRN, Monash University - Department of Infectious Diseases, Children’s Hospital at Westmead - The National Centre for Immunisation Research and Surveillance (NCIRS), Monash University, Queensland Children's Hospital - Infection Management Service, University of Melbourne - Infection and Immunity, Charles Darwin University - Menzies School of Health Research, Children’s Hospital at Westmead - The National Centre for Immunisation Research and Surveillance (NCIRS), University of Adelaide - Vaccinology and Immunology Research Trials Unit, Children’s Hospital at Westmead - The National Centre for Immunisation Research and Surveillance (NCIRS) and Perth Children’s Hospital - Wesfarmer's Centre for Vaccines and Infectious Diseases