Fig 4. In ovo delivered CpG DNA induces protective host response against ILTV infection encountered post-hatch.

SPF ED18 eggs were delivered with CpG DNA (n = 8) or non-CpG DNA (n = 7) in ovo, the eggs were incubated to hatch and infected with ILTV intra-tracheally at day 1 post-hatch. The chickens were observed for 12 days. At 4 days post-infection, oropharyngeal and cloacal swabs were collected and ILTV genome loads quantified. a) Survival percentage, b) clinical scores, c) ILTV genome loads in cloacal swabs and d) ILTV genome loads in oropharyngeal swabs. Log-rank test was used to identify differences in survival percentages, Mann-Whitney U test was used to identify differences in clinical score data and student's t-test was used to identify differences in ILTV genome loads. The differences were considered significant at P< 0.05. The bars represent median ± inter quartile range in Fig. 4b and mean ± SEM in Fig. 4a, c and d.