Scatter plot of concentrations of ILTV as determined by qPCR on extracts from conjunctival or tracheal swabs of unvaccinated birds and birds vaccinated with different doses of ΔgG ILTV at day 7 after challenge with class 9 ILTV.

Values labelled with the same upper-case letter (A, B, C) were not significantly different (P > 0.05, one-way analyses of variance in conjunction with Dunnett’s Multiple Comparisons test) in each panel (conjunctiva or trachea). GCN = genome copy number, UnVx-Uch = unvaccinated and unchallenged, UnVx-Ch = unvaccinated and challenged, PFU = plaque forming units. Means (horizontal solid lines) and standard deviations (error bars) are also shown. The cut off value for positivity was 100 genome copies per reaction and this is indicated by a horizontal dashed line.