FIG. 5.

The Δ22 virus exhibits a replication defect in MDBK cells compared to Vero cells. (A) Monolayers of Vero cells were infected with WT or Δ22 virus at a multiplicity of 0.1. At various times after infection, total virus was harvested by combining the cells and medium, and the samples were titrated on Vero cells. (B) Monolayers of MDBK cells were infected with WT, Δ22, or Δ22R virus at a multiplicity of 0.02. At various times after infection, total virus was harvested by combining the cells and medium, and the samples were titrated on Vero cells. h.p.i., hours postinfection.