IL-12, IFN-γ, TNF-α, IL-5, and IL-6 levels in murine sera. Sera were pooled from groups of five control (uninfected), B. burgdorferi-infected, or B. burgdorferi- and HGE-infected mice. IFN-γ (A), IL-12 (B), TNF-α (C), IL-6 (D), and IL-5 (E) levels were analyzed by capture ELISA. Results from one of three comparable experiments are presented. ∗, P < 0.05 using Student's t test, as stated in the text. Error bars indicate standard deviations.