To date, investigation of the immune response in marmosets has primarily been achieved using pathogen-specific antibodies to determine the serological response using ELISA such as in the smallpox, Dengue, Rift Valley Fever, and Herpes models [5, 6, 8, 17] or by immunohistochemistry to identify, for example, CD8+, CD3+, CD20+ cells, and IL-6 in the smallpox model [17]; neutrophils and macrophages in the Herpes model [6]; or CD3+ and CD20+ cells in the Lassa model [3]. Here, IL6 is linked to smallpox.