Figure 4
Comparison of PPR virus neutralization test using rPPRV/GFP and PPRV/N75/1. (A) Detection of virus replication during VNT assay. Serum from a goat (no. 31) previously vaccinated with 107 TCID50 PPRV/N75/1 was tested using either rPPRV/GFP or PPRV/N75/1. The GFP fluorescence ((i) to (iv)) and CPE ((ix) to (xii)) of rPPRV/GFP or the CPE of PPRV/N75/1 ((xiii) to (xvi)) after treatment with diluted serum (320-fold) were observed at 4, 6, 10 and 14 d post-infection. (B) Twenty PPRV-positive sera from rCPV-PPRVH vaccinated goats (nos. 1–10) or sheep (nos. 11–20) were assayed for PPR VNA titer using PPRV/N75/1 and rPPRV/GFP. (C) Ten positive sera from PPRV/N75/1 vaccinated goats (nos. 21–30) were assayed in the same manner as above. The results from assays with the two viruses were compared using a paired t test, and no significant difference seen