Efficacy of intranasal vaccines containing bovine corona virus or bovine respiratory syncytial virus and parainfluenza virus type 3 in young calves with or without maternally derived antibodies

Bovine respiratory syncytial virus, bovine parainfluenza type 3 virus, and bovine corona virus cause respiratory disease in calves during the first weeks of life and protection should be achieved as young as possible to cover the period with the highest risk. Maternal antibodies present in the colostrum that calves receive immediately after birth may result in positive serum antibody titers against these viruses which may interfere with vaccination. However, in this investigation we show that two new intranasal vaccines containing these three, live viral attenuated viruses can provide protection in calves with or without maternally derived antibody titers at a very young age.