DEVELOPMENT OF PROTOTYPE SINGLE-CYCLE VACCINES FOR BOVINE RESPIRATORY SYNCYTIAL VIRUS

We have previously developed a pioneer live-attenuated mucosal vaccines platform for human RSV (hRSV) and propose translating our technology to create a prototype for the BRSV counterpart. We aim to develop this prototype vaccine and assess immunogenicity vaccine efficacy and protection against virulent BRSV in calves. Multiple vaccines are currently marketed for BRSV, including for parenteral and mucosal delivery, but variable efficacy and safety concerns have been reported. Parenteral vaccine delivery faces interference by MDA that hampers vaccine uptake and diminishes responses to vaccination. Moreover, current live attenuated vaccines (including nasal delivered) are replication competent, retaining the risk of reversal to- and residual -virulence.The success of this vaccine would significantly improve cattle health, reduce antibiotic use associated with secondary infection in cattle, and increase production efficiency, contributing to food safety and nutrition security. The objectives of this study are related to the program area of Animal Health and Disease (Priority code A1221). Successful completion of this work will significantly impact the priority areas of "disease prevention" by developing improved "vaccination delivery systems and/or vaccines" for use in livestock species.To achive this goal, our objectives are:Generation of Mnull BRSV single-cycle vaccine.Generation of preF BRSV single-cycle vaccine.Immunogenicity and efficacy of single-cycle BRSV vaccines in calves.