Fig 8.

Viral-RNA loads in serum samples at 7 and 14 days and in lung tissues at 14 days p.c. from the challenge/protection study in pigs vaccinated with the chimeric viruses (DS722 or DS5M3), followed by challenge. (A) PRRSV viral-RNA loads in serum samples from pigs at 7 days p.c. with a homologous PRRSV, VR2385, or a heterologous PRRSV, NADC20. (B) PRRSV viral-RNA loads in serum samples from pigs at 14 days p.c. with PRRSV VR2385 or NADC20. (C) PRRSV viral-RNA loads in the lung tissues from pigs at 14 days p.c. Significant differences are indicated with asterisks (*, P < 0.05; **, P < 0.01; ***, P < 0.001). In all three panels, the numbers within circles along the x axis indicate the numbers of animals in each group that tested negative for serum viral RNA.