1 Departments of Emergency Medicine and Pediatrics, School of Medicine, University of California Davis, Sacramento, California; nkuppermann@ucdavis.edu.
2 Department of Emergency Medicine, Medical School, University of Michigan, Ann Arbor, Michigan; and.
3 Division of Pediatric Infectious Diseases, Center for Vaccines and Immunity, Nationwide Children's Hospital and School of Medicine, The Ohio State University, Columbus, Ohio.