Figure 5.

Reduced virus shedding and reduced viral burden in SCFP-treated calves compared with controls. (A) Nasal swabs were collected from all animals (n = 10 controls, n = 12 SCFP-treated calves) on days 0, 1, 3, 7, and 10 and snap-frozen at −80 °C until analysis. Swabs were analyzed by qPCR for the BRSV NS2 gene. NS2 mRNA was undetectable on day 0 of the infection. Results from days 3, 7, and 10 are depicted in the graph. Only 6/10 control calves and 3/12 SCFP-treated calves were positive for viral RNA on day 10 postinfection. Data are presented as means ± SEM. *P = 0.049. (B) The animals were humanely euthanized on day 10 postinfection. Sections of the healthy and pneumonic lung were collected from 2 to 3 representative lesion sites of the lungs and preserved in RNALater. The RNA was extracted using Trizol reagent and samples from multiple sites were then pooled and analyzed by qPCR for the BRSV NS2 gene. NS2 copy number was normalized to the housekeeping gene, S9, to correct for differences in the input material. Statistical significance was interrogated by student’s t-test.