1. Department of HIV/AIDS, World Health Organization, 20 Avenue Appia, 1211 Geneva, Switzerland.
2. Office of the Global AIDS Coordinator, United States Department of State, Washington DC, United States of America.
3. Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland.
4. Department of HIV, TB and Hepatitis, Communicable Diseases Cluster, World Health Organization Regional Office, Harare, Zimbabwe.