Fig. 4.

LAIV vaccination induces a Type 1 memory response in human subjects. Peripheral blood samples were taken 1 week prior to and 4, 7 and 11 weeks after administration of LAIV. PBMCs were isolated and cultured with the LAIV or with medium alone (2 × 10⁶/200 μl per well). Supernatants were collected after 24 h and cytokine concentrations were determined by the Luminex multiplex system. For each cytokine, background production (from medium alone cultures) was subtracted from the values for the LAIV stimulated cultures. Each symbol represents an individual person (*p < 0.05, **p < 0.0001 by paired Student’s t test comparing each time point to prevaccination values) and bar depicts group mean.