1. Country Office, World Health Organization , Abuja , Nigeria
2. National Institute for Public Health and the Environment , Bilthoven , the Netherlands
3. National Bureau of Statistics , Abuja , Nigeria
4. Groningen Research Institute of Pharmacy, University of Groningen , the Netherlands
5. African Regional Office, World Health Organization , Brazzaville, Congo
6. Department of Paediatric Immunology and Infectious Diseases, University Medical Centre Utrecht , the Netherlands