Host Infection History in Lyme Disease

Could Block, Enhance Transmission of Lyme Bacterium

NIAID scientists have learned that the infection history of mammals fed upon by ticks that spread the Lyme disease bacterium can have a significant influence on future infection. If the host, such as a mouse, already has been infected with the same strain of Borrelia burgdorferi that the tick carries, antibodies from the host would bind to and neutralize the bacterium within the tick midgut. If the tick carried a different strain of B. burgdorferi than the host was infected with, then the host would become “super-infected” with both strains. The finding demonstrates that an effective vaccine targeting strain-specific components of Lyme disease can neutralize bacteria within the tick, but would need to be specifically designed to protect against multiple strains.