1. Bandim Health Project, Indepth Network, codex 1004, Bissau, Guinea-Bissau
2. Department of Infectious Diseases, Hvidovre Hospital, DK-2650 Copenhagen, Denmark
3. Research Center for Vitamins and Vaccines (CVIVA), Statens Serum Institut, DK-2300 Copenhagen, Denmark
4. Department of Paediatrics and Adolescent Medicine, Rigshospitalet, DK-2100 Copenhagen, Denmark
5. OPEN, University of Southern Denmark/Odense University Hospital, DK-4000 Odense, Denmark