Body temperatures, virus load and acute phase proteins after challenge infection of pigs vaccinated with a mixture of VSVΔG(GP5/M) and VSVΔG(GP4/GP3/GP2) or with VSV*ΔG as control. Two groups of 4 and 3 SPF pigs were vaccinated two times at 28 days interval with a mixture of 107 PFU/pig of the VSVΔG(GP5/M) and VSVΔG(GP4/GP3/GP2) VRP or with the VSV*ΔG mock control, respectively. 26 days after the 2nd vaccination, the pigs were infected intranasally with 106 PFU/pig of the homologous Olot/91 virus. The body temperatures A, B are shown for the individual animals. Blood was collected at the indicated days post infection. PRRSV load in serum was determined by real-time RT-qPCR (C) and by virus titration in MARC-145 cells (D), and the values expressed in 45-Cq and TCID50/mL serum (detection limit 1.7 log10 TCID50/mL), respectively. The serum concentrations (µg/mL) of the porcine acute phase proteins CRP (E) and Hp (F) were determined by ELISA. The data of panels C–F represent the mean of four and three pigs per group respectively, with error bars representing the SD and asterisks showing significant differences (p < 0.05).