1. Department of Public Health & Community Medicine, Tufts University School of Medicine, Boston, MA, USA
2. Hubert Department of Global Health, Emory University Rollins School of Public Health, Atlanta, GA, USA
3. Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, GA, USA
4. Emory Vaccine Center, Emory University, Atlanta, GA, USA