Maternal Antibodies Provide Bank Voles with Strain-Specific Protection against Infection by the Lyme Disease Pathogen

Many microbial pathogen populations consist of multiple strains that induce strain-specific antibody responses in their vertebrate hosts. Females can transmit these antibodies to their offspring, thereby providing them with short-term strain-specific protection against microbial pathogens. We investigated this phenomenon using multiple strains of the tick-borne microbial pathogenBorrelia afzelii and its natural rodent reservoir host, the bank vole, as a model system. We found that female bank voles infected withB. afzelii transmitted to their offspring maternal antibodies that provided highly efficient but strain-specific protection against a natural tick bite challenge. The transgenerational transfer of antibodies could be a mechanism that maintains the high strain diversity of this tick-borne pathogen in nature.