Representative histological images of the average level of inflammation observed in each treatment group (control, pepA, pepB, pepC, and pepD) after immunization and/or infection with the low (10³ spirochetes/mouse) or high (10⁵ spirochetes/mouse) doses in the tibiotarsal joint (A) and the heart (B).

<p>Tissues were histologically evaluated at four weeks post priming, as well as four weeks post needle inoculation. Average scores for areas of inflammation were classified as 0 = none; 1 = minimal; 2 = mild; 3 = moderate; 4 = severe. Peptide B induces minimal inflammation in hearts and tibiotarsal joints after administration in the mouse model for Lyme disease. Of all the peptides evaluated after immunization, only peptide B showed inflammation comparable to the negative control group in both heart and joints. Similar results were observed after infection with low doses of <i>B. burgdorferi</i>. Images were captured using an Olympus BX41 microscope at 200X magnification. Average ± SD are presented in the graphs.