The effect of bovine vaccines against respiratory viruses administered either intranasal or intramuscular on broncho-alveolar fluid cells of heifers.

Background: The knowledge on bovine vaccines against respiratory viruses on bronchoalveolar fluid cells is scarce.

Objective: To compare the effects of a commercial intranasal (IN) and intramuscular (IM) vaccine against bovine respiratory disease (BRD) complex viruses on bronchoalveolar fluid cells of healthy heifers.

Methods: 21 healthy heifers were assigned to three treatment groups: control (CO, N = 7), intranasally vaccinated (IN) (n = 7), and intramuscularly vaccinated (IM) (n = 7).