1. Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA.
2. Asociacion Civil Impacta Salud y Educacion, Lima, Peru.
3. Centro de Investigaciones Tecnológicas, Biomédicas y Medioambientales, Lima, Peru.
4. Universidad Nacional Mayor de San Marcos, Lima, Peru.
5. Department of Medicine (RBI), Global Health (AD, JRL), and Epidemiology (RBI and AD), University of Washington, Seattle, Washington, USA.