Deployment of a reservoir-targeted vaccine against Borreliella burgdorferi reduces the prevalence of Babesia microti coinfection in Ixodes scapularis ticks.

In the northeastern and upper Midwestern United States, Babesia microti and Borreliella burgdorferi use Ixodes scapularis ticks as vector and Peromyscus leucopus mice as major reservoir host. We previously established, in a 5-year field trial, that a reservoir-targeted OspA vaccine reduces the prevalence of B. burgdorferi-infected ticks. We accessed ticks and mouse blood samples collected during the trial, extracted DNA and amplified the B. microti 18S rRNA gene. Vaccine deployment reduced the prevalence of ticks coinfected with B. microti and that of mice infected with B. microti. Breaking the enzootic cycle of B. burgdorferi may reduce the incidence of babesiosis.