aGlobal Health Impact Group, Atlanta, GA;bVaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA;cUniversity of Cape Town, Cape Town, South Africa;dCentral Public Health Laboratory, Kampala, Uganda;eNational Health Laboratory Service, Johannesburg, South Africa;fDepartment of Immunology and Infectious Diseases, Harvard Medical School, Boston, MA; andgDepartment of HIV/AIDS, World Health Organization, Geneva, Switzerland.