Figure 7. Detection of H7 HA-specific IgG (A), IgA (B), and IgM (C) antibody responses in H7N9 patients (pt-1, pt-2 and pt-3) by ELISA. Patient sera were collected from 3 H7N7 patients: patient 1 (pt-1) at day 11, patient 2 (pt-2) at day 13 or patient 3 (pt-3) at day 16 after onset of fever; normal human sera (NHS) served as negative control. Antibody responses in each patient serum sample were measured against 293T cells supernatant transfected with H7-HA-dTM (A/Netherlands/219/03) DNA vaccine or empty vector (Mock), as indicated.