Values of virus shedding (a) and rhinitis severity (b) in vaccinated cattle after challenge. Virus shedding titers are expressed as log10 TCID50 per ml nasal fluid. (b) Each point in the graph is a average and SEM of the score taken in all the animals of each group. Rhinitis severity is score as follows: 0, absence; 1, slightly serous; 2, severely serous; 3, seromucous; 4, mucopurulent. References in this figure are as described in Figure 3.