National Health Laboratory Services (NHLS) - Centre for Respiratory Diseases and Meningitis, National Health Laboratory Services (NHLS) - Centre for Respiratory Diseases and Meningitis, National Health Laboratory Services (NHLS) - Centre for Respiratory Diseases and Meningitis, Centers for Disease Control and Prevention (CDC) - Influenza Division, National Health Laboratory Services (NHLS) - Centre for Respiratory Diseases and Meningitis, National Health Laboratory Services (NHLS) - Centre for Respiratory Diseases and Meningitis, National Health Laboratory Services (NHLS) - Centre for Respiratory Diseases and Meningitis, University of the Witwatersrand - Perinatal HIV Research Unit, University of the Witwatersrand - MRC/Wits Rural Public Health and Health Transitions Research Unit, University of the Witwatersrand - Perinatal HIV Research Unit, Chris Hani Baragwanath Academic Hospital - Perinatal HIV Research Unit, University of the Witwatersrand - MRC/Wits Rural Public Health and Health Transitions Research Unit, University of the Witwatersrand - MRC/Wits Rural Public Health and Health Transitions Research Unit, National Health Laboratory Services (NHLS) - Centre for Respiratory Diseases and Meningitis, National Health Laboratory Services (NHLS) - Centre for Respiratory Diseases and Meningitis, National Health Laboratory Services (NHLS) - Centre for Respiratory Diseases and Meningitis, South African Medical Research Council - Health Systems Research Unit, North-West University - Unit for Environmental Sciences and Management, North-West University - Unit for Environmental Sciences and Management, National Health Laboratory Services (NHLS) - Centre for Respiratory Diseases and Meningitis, Government of the United States of America - Division of Influenza and Independent