The Contractor is developing Burkholderia-derived outer membrane vesicles (OMVs), containing a naturally-attenuated lipid A, as a vaccine adjuvant. This research will develop the adjuvant within the context of a vaccine to prevent Lyme disease in humans. Borrelia burgdorferi is the etiologic agent of Lyme disease, which is transmitted by the bite of Ixodes ticks. There are no currently approved vaccines that prevent Lyme disease in humans.