[1] Univ Adelaide, Sch Populat Hlth Paediat & Reprod Hlth, Adelaide, SA 5005, Australia
[2] Womens & Childrens Hosp, Vaccinol & Immunol Res Trials Unit VIRTU, Adelaide, SA 5006, Australia
[3] Univ Adelaide, Data Management & Anal Ctr, Discipline Publ Hlth, Adelaide, SA 5005, Australia
[4] Univ Adelaide, Discipline Publ Hlth, Adelaide, SA 5005, Australia
[5] Univ Adelaide, Robinson Inst, Adelaide, SA 5005, Australia
[6] Univ Adelaide, Sch Paediat & Reprod Hlth, Adelaide, SA 5005, Australia