[1] Childrens Hosp, Ctr Immunisat Res, Natl Ctr Immunisat Res & Surveullance, Westmead, NSW 2145, Australia
[2] Univ Sydney, Sch Publ Hlth, Fac Med, Sydney, NSW 2006, Australia
[3] Univ Sydney, Discipline Paediat & Child Hlth, Fac Med, Sydney, NSW 2006, Australia
[4] Univ Antwerp, Dept Epidemiol & Social Med, Ctr Evaluat Vaccinat, B-2020 Antwerp, Belgium
[5] Hlth Protect Agcy, Modelling & Econ Unit, Ctr Infect, London, ON, Canada