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

The percentage of infected offspring depends on the maternal antibody status of the offspring and on the strain with which they were challenged. MatAb⁻ (left) and MatAb⁺ (right) refer to the offspring from the uninfected control mothers and the mothers infected with B. afzelii strain NE4049, respectively. The offspring were challenged via tick bite with either B. afzelii strain NE4049 or B. afzelii strain Fin-Jyv-A3 at 35 days postbirth (PB). The infection status of the offspring was determined using 6 different offspring infection criteria at 35 days postinfection (p.i.) and at 70 days p.i., which correspond to 70 days PB and 105 days PB, respectively. The MatAb⁻ offspring were equally susceptible to both strains. The MatAb⁺ offspring were protected against the maternal strain (NE4049) but not the new strain (Fin-Jyv-A3). The gray solid bars show the means, and the dashed bars show the 95% confidence intervals.

The B. afzelii-specific IgG antibody response of the offspring at 35 days postinfection (p.i.) depends on the maternal antibody status and the challenge strain. MatAb⁻ (left) and MatAb⁺ (right) refer to the offspring from the uninfected control mothers and the mothers infected with B. afzelii strain NE4049, respectively. The offspring were challenged via tick bite with either strain NE4049 or strain Fin-Jyv-A3 at 35 days postbirth (PB). The MatAb⁻ offspring were equally susceptible to both strains. The MatAb⁺ offspring were protected against the maternal strain (NE4049) but not the new strain (Fin-Jyv-A3). The control group refers to 2 MatAb⁻ offspring that were each infested with 4 uninfected I. ricinus nymphs. These two individuals show the baseline B. afzelii-specific IgG antibody response for bank vole offspring that were bitten by ticks but not infected with B. afzelii. Shown are the medians (black lines), the 25th and 75th percentiles (edges of the box), the minimum and maximum values (whiskers), and the outliers (circles).