Figure 2. Production of cytokines IFN-γ, TNF-α, IL-2, IL-4, IL-5, and IL-6 and chemokines IL-8, MCP-1 and RANTES in Chinese-origin rhesus macaques immunized with the Y. pestis strain 201 and the EV on week 2, 4, 6, and 8 post immunization. Cytokine or chemokine production was calculated by subtracting the cytokine or chemokine concentration in control animals from the concentration measured in the Y. pesti 201- or the EV-immunized animals.