Protective efficacy of an oral vaccine to reduce carriage of Borrelia burgdorferi (strain N40) in mouse and tick reservoirs

Lyme disease is caused by the spirochete Borrelia burgdoifieri, which is transmitted through the bite of infected Ixodes ticks. Vaccination of mice with outer surface protein A (OspA) of B. burgdoiferi has been shown to both protect mice against B. burgdorferi infection and reduce carriage of the organism in feeding ticks. Here we report the development of a murine-targeted OspA vaccine utilizing Vaccinia virus to interrupt transmission of disease in the reservoir hosts, thus reducing incidence of human disease. Oral vaccination of mice with a single dose of Vaccinia expressing OspA resulted in high antibody titers to OspA, 100% protection of vaccinated mice from infection with B. burgdolferi, and significant clearance of B. burgdoiferi from infected ticks fed on vaccinated animals. The results indicate the vaccine is effective and may provide a manner to reduce incidence of Lyme disease. (c) 2005 Elsevier Ltd. All rights reserved.