Intradermal administration of the vaccines for anthrax (rPA), botulism [BoNT/A(H
)], plague (rF1-V), and SEB induced toxic-shock (STEBVax). A. Rhesus macaque skin immediately after vaccination (two sites, left to right): BoNT/A, rF1-V, rPA, and STEBVax. B. Rhesus macaque skin two months after vaccine administration. Marks are adjacent to injection sites. C. Skin sections (H&E stain) obtained from the vaccine delivery site exhibited epithelioid macrophages and multinucleated giant cells containing adjuvant (inset, green). Phalloidin staining of actin, red; Hoechst staining of DNA, blue. D. Macrophages at the vaccine delivery site exhibited high expression of MHC-II molecules (brown). Anti-MHC Class II immunohistochemistry (brown). E. Epithelioid macrophages (H&E stain) containing adjuvant (inset) were also present in the axillary lymph nodes of vaccinated animals. F. Vaccination did not significantly alter white blood cell counts of vaccinated animals (solid line) compared to control (dashed line). Mean cell counts ± SD of all animals studied.