1 Vaccine Research Center, National Institutes of Health, Bethesda, MD, USA. rkoup@mail.nih.gov.
2 Biomedical Advanced Research and Development Authority, US Department of Health and Human Services, Office of the Assistant Secretary for Preparedness and Response, Washington, DC, USA. ruben.donis@hhs.gov.
3 Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA.
4 Boston Consulting Group, Summit, NJ, USA.
5 Biomedical Advanced Research and Development Authority, US Department of Health and Human Services, Office of the Assistant Secretary for Preparedness and Response, Washington, DC, USA.