No vaccine interference between bovine coronavirus and bovine herpesvirus-1 in a randomized trial when coadministrating two intranasal modified-live viral vaccines to neonatal calves.

Objective: Compare immune responses induced by 2 commercial intranasal (IN) modified-live viral (MLV) vaccines given individually or coadministered and evaluate prevention of infection and lung pathology following bovine herpesvirus-1 (BHV-1) challenge.

Animals: 36 male Holstein calves (ages, 5 to 12 days).

Methods: In a randomized complete block design, each calf received an IN injection of either vaccine diluent (Placebo), an MLV vaccine containing bovine herpesvirus-1 (BHV-1; N3), bovine coronavirus vaccine (BC), or both N3 and BC (BC + N3) with a booster 4 weeks later.