1. Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, Canada;
2. Hospital Universitario La Paz, IdiPAZ, Madrid, Spain; and
3. University of Texas Medical Branch at Galveston,
4. Diagnostics Research Group, San Antonio,
5. Benchmark Research, Austin, Texas, and
6. Merck & Co, Inc, Kenilworth, New Jersey