Evaluation of IBR Vaccine Virus Shedding After Parenteral Administration to Suckling Calves
DOI:
https://doi.org/10.21423/aabppro19965988Keywords:
IBR vaccine, abortigenic, modified live IBR vaccines, shedding, transmission, immunosuppression, parenteral vaccinationAbstract
Many vaccine strains of IBR are assumed to be abortigenic. There is therefore concern about administering modified live IBR vaccines to suckling calves because of the possibility of shedding of the vaccine virus by vaccinates and subsequent transmission to the pregnant dam. The purpose of Phase I of this study was to show whether IBR MLV vaccine strain RT-22 causes virus shedding after parenteral vaccination of IBR-susceptible calves. Phase II of the study was designed to show whether immunosuppression 90 days after vaccination would result in recrudescence of the vaccine virus and subsequent viral shed.