ABSTRACTThe objective of the present study was to compare the effects of the modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine (Ingelvac PRRS MLV; Boehringer Ingelheim Animal Health, St. Joseph, MO) on European and North American PRRSV shedding in the semen of experimentally infected boars. The boars were randomly divided into six groups. Vaccinated boars shed the North American PRRSV at the rate of 100.1to 101.0viral genome copies per ml and 3.63 to 101.150% tissue culture infective doses (TCID50)/ml, respectively, in semen, whereas nonvaccinated boars shed the North American PRRSV at the rate of 100.2to 104.7viral genome copies per ml and 1.14 to 103.07TCID50/ml, respectively, in semen. Vaccinated boars shed the European PRRSV at the rate of 100.1to 104.57viral genome copies per ml and 1.66 to 103.10TCID50/ml, respectively, in semen, whereas nonvaccinated boars shed the European PRRSV at the rate of 100.3to 105.14viral genome copies per ml and 1.69 to 103.17TCID50/ml, respectively, in semen. The number of genomic copies of the European PRRSV in semen samples was not significantly different between vaccinated and nonvaccinated challenged European PRRSV boars. The present study demonstrated that boar vaccination using commercial modified live PRRSV vaccine was able to decrease subsequent shedding of North American PRRSV in semen after challenge but was unable to decrease shedding of European PRRSV in semen after challenge.
T-cell epitopes predicted from the Nucleocapsid protein of Sin Nombre virus restricted to 30 HLA alleles common to the North American population