[1] Univ Rochester, Sch Med & Dent, Dept Community & Prevent Med, Rochester, NY USA
[2] Univ Rochester, Sch Med & Dent, Dept Pediat, Rochester, NY 14642 USA
[3] Univ Rochester, Sch Med & Dent, Dept Biostat, Rochester, NY 14642 USA
[4] Northwestern Univ, Childrens Mem Hosp, Dept Pediat, Chicago, IL 60614 USA
[5] Northwestern Univ, Childrens Mem Hosp, Inst Hlth Serv Res & Policy Studies, Chicago, IL 60614 USA
[6] Ctr Dis Control & Prevent, Natl Immunizat Program, Atlanta, GA 30333 USA