Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA.|Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA.|Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA.|Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA.|Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA.|Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA.