Cell mediated immunity to bovine rhinovirus type 1 in calves.

Calves experimentally infected with bovine rhinovirus type 1 developed a mild respiratory disease and exhibited a cell mediated immune (CMI) response, as determined by leukocyte migration inhibition (LMI) and lymphocyte blastogenesis tests. The CMI response to the virus was detected by day 3 post-inoculation using direct and indirect LMI tests. It persisted through day 28, with maximal responses occurring between days 4 and 14. Measurement of cellular immunity by blast transformation, however, was not evidenced until day 12. The humoral antibody response was minimal with serum neutralizing titers ranging from 1:4 to 1:16 and this response was not evident until 3 weeks after inoculation.