Five mice were euthanized 14 days following a 2° L2R infection, C. trachomatis serovar D infection, or sham infection (SPG). The entire genital tract was removed for histopathological evaluation. Micrographs of histological sections of the cervical region from L2R immunized mice (A, B); Serovar D infected (C, D) and sham infected (E, F) are shown. Magnification 40×: (A, C, E) and 400× (B, D, F). Note that there were no pathological changes in L2R or sham infected mice. In contrast, infection with C. trachomatis serovar D produced a moderate sub-mucosal infiltrate presented as multifocal aggregates composed of lymphocytes, macrophages and plasma cells. Occasionally, low numbers of these cellular aggregates were present within the epithelium lining the lumen. Similarly, smaller and less densely arranged inflammatory aggregates were noted in the muscular layers.