Figure 3

In vitro proliferations of lymphocytes from vaccinated chickens in response to recall inactivated H7N9 antigen. Chickens (N = 12) were immunized with Sal-vector, Sal-HA, Sal-M2e, Sal-M2e-NA or Sal-HA-M2e-NA vaccine, and PBMCs from vaccinated chickens after 14 days post-immunization were restimulated with inactivated H7N9 antigen (5 µg/mL) for 72 h and lymphocyte proliferation was determined by MTT assay. Results are expressed as stimulation indices, defined as proliferation in response to recall antigen relative to the mock stimulated cells. Each data points represent mean ± SD of five chickens per group.*p < 0.05. ns: non-significant.