Figure 2.

Survival and weight changes in BALB/c mice with and without low-dose Cy immunosupression. Mice were vaccinated with TBE vaccine Tick-E-Vac and challenged with 100 LD₅₀ of TBEV strain Vasilchenko. (a) Survival curves for vaccinated and control mice. (b) Weight changes after the virus challenge. Error bars represent SEM. Group Vac-Vac was vaccinated twice without Cy treatment (green); group Cy-Vac-Vac received Cy before the first vaccine dose (blue); group Vac-Vac-Cy received Cy after the vaccination and immediately before the challenge (pink); Virus—a control non-vaccinated group (violet). In all vaccinated groups, the vaccine was i/m administered twice (50 mkl/mouse) with a two-week interval; the virus challenge was carried out two weeks after the second vaccination. Cy was i/p administered twice at doses 60mg/kg and 30 mg/kg with a one-day interval. For all groups, N = 15. Data only for mice surviving till 21 dpi was used for weight curves. * All brain samples from dead mice were considered RNA-positive. Statistical significance for mortality data was determined by log rank test (**** p < 0.0001).