National Health Laboratory Services (NHLS) - Centre for Respiratory Diseases and Meningitis, ISI Foundation, ISI Foundation, Independent, University of the Witwatersrand, National Health Laboratory Services (NHLS) - National Institute for Communicable Diseases, University of the Witwatersrand - Perinatal HIV Research Unit, University of the Witwatersrand - Department of Clinical Microbiology and Infectious Diseases, 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, ISI Foundation and Government of the United States of America - Division of Influenza