Protection of young calves from BRSV in the presence of maternal antibodies

John Ellis (Department of Veterinary Microbiology, University of Saskatchewan, Canada) and the HIPRA R&D team worked together in the design of this peer-reviewed study while Ellis performed the experimental trial.

The purpose of this study was to examine:

1. The efficacy in protecting calves from a virulent BRSV challenge after intranasal administration of NASYM (live vaccine against Bovine Respiratory Syncytial Virus) to MDA + calves in the first 2 weeks of life.

2. The longevity of the clinical immunity.

3. To characterize the immunological response to the vaccine before and after challenge.

Take a look at the amazing results obtained by J. Ellis which can help vets and farmers when facing BRSV:

Conclussions of the study:

The efficacy of NASYM vaccine against a virulent BRSV challenge was demonstrated in newborn calves vaccinated at the age of 7 to 17 days.

Protection was shown in terms of clinical signs, lung lesions, viral shedding, mortality, PaO2 and humoral response.

The longevity of the immunity was demonstrated at least until 10 weeks of age in the presence and the absence of MDA.