1. Vaccine Research Center, NIH/NIAID, Bethesda, Maryland, USA
2. Biostatistics Research Branch, NIH/NIAID, Bethesda, Maryland, USA
3. Bridge Laboratories, Gaithersburg, Maryland, USA
4. Althea Technologies, Inc., San Diego, California, USA
5. MedImmune, Inc., Gaithersburg, Maryland, USA
6. PRTM, Washington, DC, USA