Fig. 4From: Construction of a quadruple gene-deleted vaccine confers complete protective immunity against emerging PRV variant challenge in pigletsDetection of neutralizing antibodies in immunized pigs. The neutralizing antibody titers against the PRV GDFS strain (A) or PRV Ea strain (B) were calculated and are expressed as the highest dilutions that resulted in complete inhibition. All data are expressed as mean ± SEM. The asterisk (*) indicates statistically significant differences between different groups (P < 0.05)Back to article page