[1] Indepth Network, Bandim Hlth Project, Bissau, Guinea Bissau
[2] Univ Southern Denmark, Odense Univ Hosp, Inst Clin Res, OPEN, Odense, Denmark
[3] Statens Serum Inst, Res Ctr Vitamins & Vaccines, Bandim Hlth Project, DK-2300 Copenhagen, Denmark
[4] Univ British Columbia, Child & Family Res Inst, Dept Pediat, Div Infect Dis, Vancouver, BC V5Z 1M9, Canada