Table 1.
Primers used in the quantitative real time PCR.
Table 2.
Recovery of live virus from challenged ducks (positive/total).
Fig 1.
Serum hemagglutination inhibition (HI) levels in vaccinated-challenged ducks.
Serum samples (20 ducks per group) were collected at 7-, 14-, 21- and 28-day post-vaccination, and at 3-, 5- and 7-day post-challenge. Antibody titers were determined using the HI assay with 4 HA units of the SIC12/13, SIC9/13 and SIC10/13 avian influenza virus strain, respectively. The HI titer is expressed as the log2 form.Bars indicate mean ± SEM of a representative experiment. (*P<0.05, **P<0.01, ***P<0.001). Experimental groups are as in Table 2.
Fig 2.
The mRNA expression levels of immune genes in duck spleens.
Spleens of ducks immunized with H9 vaccine, H9-PIC vaccine and PBS were harvested for RNA isolation at 7-, 14-, and 28-day post-vaccination. The mRNA levels for CD4 (A), CD8α (B), MHC-I (C), MHC-II (D), IL-2 (E), IL-6 (F), IFN-α (G) and IFN-γ (H) were evaluated by real-time PCR. Expression of target genes was normalized to those of duck β-Actin. The relative fold change was calculated using PBS injected ducks as control. Bars indicate mean ± SEM of a representative experiment. (*P<0.05, **P<0.01, ***P<0.001). Experimental groups are as in Table 2.