Fig. 5.

PRCV- and PRRSV-specific serum VN and ELISA antibody titres in pigs co-infected with PRRSV and PRCV. Serum was collected at each PID from the numbers of pigs indicated in the legend of Fig. 2. (a) Serum VN antibody titres against PRCV were evaluated by a plaque-reduction test. Antibody titres were expressed as the reciprocal of the specimen dilution that resulted in an 80 % reduction in the number of plaques. (b) PRRSV serum antibodies were identified by a commercial PRRSV ELISA (Idexx Laboratories, ME) and evaluated based on progression of the S : P ratios. Each data point represents the mean±sem.