Interferon, antibody responses and protection induced by an intranasal infectious bovine rhinotracheitis vaccine.

The interferon and antibody response induced by an intranasal infectious bovine rhinotracheitis vaccine was followed in 22 calves over a nine month period and the ability of these vaccinated calves to withstand challenge with virulent infectious bovine rhinotracheitis virus was assessed. Interferon was detected two to three days post-vaccination and disappeared by the tenth day. Nasal and serum antibodies appeared by day 7 and persisted for nine months. The calves challenged three days postvaccination came down with disease typical of infectious bovine rhinotracheitis, whereas calves challenged three weeks, three months or nine months postvaccination resisted infection.