1. Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.
2. Department of Biomedical Sciences, School of Public Health and Community Development, Maseno University, Kisumu, Kenya.
3. Department of Microbiology and Immunology, Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA.
4. Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
5. Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA.
6. Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA.