Figure 5.

Safety profile of the WT MDV A/AA/6/60 LAIV and mutant MDV A/AA/6/60 LAIVs in vivo: Four-to-six-week-old female C57BL/6 mice (n = 11) were infected i.n. with 1 × 10⁵ FFU of the WT MDV A/AA/6/60 LAIV (PA_WT⁺/NS1_WT⁺) or the mutant MDV A/AA/6/60 LAIVs (PA_WT⁺/NS1_MT⁻, PA_MT⁻/NS1_WT⁺, and PA_MT⁻/NS1_MT⁻). Body weight (A) and survival (B) were monitored for 14 days (n = 5). At Days 2 and 4 p.i., C57BL/6-infected mice were sacrificed (n = 3 per time point) and viral titers were determined in lungs (C) and nasal turbinates (D) by immunofocus assay using the anti-NP mAb HB-65. Symbols represent data from individual mice. Bars represent the mean for each group and indicates that the virus was only detected in one or two of the infected mice. N.D. indicates that virus was not detected. Dotted lines represent the limit of detection of the assay (200 FFU/mL).