[1] Univ Sydney, Natl Ctr Immunisat Res & Surveillance Vaccine Pre, Childrens Hosp Westmead, Sydney, NSW 2145, Australia
[2] Univ Sydney, Discipline Paediat & Child Hlth, Sydney Med Sch, Sydney, NSW 2145, Australia
[3] Univ Technol Sydney, Sch Med & Mol Biosci, Sydney, NSW 2007, Australia
[4] Univ Sydney, Sch Publ Hlth, Sydney, NSW 2006, Australia
[5] Univ Sydney, Sch Biol Sci, Marie Bashir Inst Infect Dis & Biosecur, Westmead, NSW 2145, Australia
[6] Univ Sydney, Sydney Med Sch, Westmead, NSW 2145, Australia
[7] Flinders Univ S Australia, WHO Collaborating Ctr Mass Gatherings & High Cons, Adelaide, SA 5001, Australia