[1] Colorado State Univ, Dept Microbiol Immunol & Pathol, Ft Collins, CO 80523 USA
[2] Univ Oxford, Nuffield Dept Med, Jenner Inst, Oxford OX1 2JD, England
[3] Yeshiva Univ Albert Einstein Coll Med, Howard Hughes Med Inst, Dept Microbiol & Immunol, Bronx, NY 10461 USA
[4] London Sch Hyg & Trop Med, Dept Immunol & Infect, London, England
[5] Infect Dis Res Inst, Seattle, WA USA
[6] Texas A&M Hlth Sci Ctr, Dept Microbial & Mol Pathogenesis, College Stn, TX USA
[7] McGill Univ, Ctr Hlth, Montreal, PQ, Canada
[8] Hlth Protect Agcy, Salisbury, Wilts, England