Figure 5.

Representative pictures showing virus-neutralizing antibody response in the plasma samples of porcine reproductive and respiratory syndrome virus (PRRSV)-infected pigs. (A) 100 TCID₅₀ of virus was used in the virus neutralization (VN) assay, which showed appreciable quantity of infected cells by immunofluorescence assay (IFA) at 24 h postinfection (N, PAMs used as negative control; Mock, mock infected; No serum, JXA-1 used as virus control. Scale bar = 50 µm.). (B) The VN antibody titers in the plasma samples collected at day 28 postvaccination were up to 8 in Tg pigs, whereas those in WT were 4. (C) VN antibody titers in plasma samples collected at day 10 postchallenge were tested again, and similar results were shown here. WT, wild-type pigs; CD28 Tg, CD28 transgenic pigs.