1. Division of Immunology and Rheumatology, Department of Medicine, Stanford University, Stanford, CA, USA.
2. Department of Medicine, Palo Alto Veterans Administration Healthcare System, Palo Alto, CA, United States.
3. Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA, USA.
4. Department of Medicine, Division of Infectious Diseases and Global Public Health, University of California, San Diego, La Jolla, CA, USA.