The aim of this project is to evaluate vaccines against bovine respiratory syncytial virus (BRSV) in young calves with maternally-derived antibodies. These antibodies originate from the first milk of the mother and can protect the calf against disease by binding to pathogens. However, the same antibodies can additionally bind to vaccines and will thereby inhibit the effect of vaccination in young calves. Bovine RSV is very contagious and causes annual outbreaks of respiratory disease in Swedish cattle. A closely related virus, the human RSV, can likewise cause serious disease in humans, mainly in infants and elderly.
While vaccines against BRSV exist for cattle, no vaccine against HRSV is available for humans. This is due to adverse effects of earlier vaccines, a weak immune system in infants and the interference with maternally-derived antibodies. However, a break-through recently occurred in RS-vaccinology. A viral protein (the fusion protein) was stabilised in a form (Pre-F) that induces strong immune responses in humans and better responses than a commercial vaccine in calves with maternal antibodies. In contrast to when using commercial vaccines, the usage of Pre-F enables disease monitoring based on serology, which currently is carried out on a voluntary basis in Sweden. With a Pre-F-based vaccine, infected animals can be differentiated from those non-infected but vaccinated, which allows tracking the virus among herds, with the possibility to warn nearby counties. Within the project, the immune response to candidate vaccines based on different parts of PreF will be evaluated in calves and the calves that will stay in the herd will be followed up throughout their life by blood sampling. If a natural BRSV-infection occurs in the herd during the lifespan of the animals, the clinical and virological protection of the vaccines will be evaluated.
Contact researchers
Jean Francois Valarcher, jean-francois.valarcher@slu.se, tel., +4618671351.
Other participants in the project
Sara Hägglund, sara.hagglund@slu.se, tel., +4618671891.