1. Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
2. Department of Women and Children's Health, University of Liverpool, Liverpool, UK
3. Kamuzu University of Health Sciences
4. Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
5. Department of Human Development and Quantitative Methodology, University of Maryland, College Park, MD, USA.