From the Vaccines Clinical Research and Development, GSK, Rockville, Maryland. Vaccine Biostatistics Department, GSK, Rockville, Maryland. Department of Pediatrics, Center of Excellence in Pediatric Infectious Diseases and Vaccines, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. Department of Pediatrics, Mackay Children's Hospital, Taipei, Taiwan. Department of Internal Medicine, Chiang Mai University, Chiang Mai, Thailand. Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan. Department of Pediatrics, Chang Gung Memorial Hospital, Chang Gung University Col-lege of Medicine, Taoyuan, Taiwan. Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan. Division of Pediatric Infectious Diseases, China Medical University College of Medicine, Children's Hospital, Taichung, Taiwan. Clinical and Epi Research and Development, GSK, Rockville, Maryland. GSK, Wavre, Belgium. Clinical Laboratory Sciences, GSK, Rixensart, Belgium. Biostatistics and Statistical Programming Department, GSK, Rockville, Maryland. Vaccines Research and Development, GSK, Rockville, Maryland. Center for Vaccine Innovation and Access, PATH, Washington, District of Columbia. Vaccine Discovery and Development, GSK, Rockville, Maryland, USA.