TABLE 1.

Prevaccination IFN-γ responses to avian PPD

Group	IFN-γ response 2 weeks prior to the onset of vaccination (ng of IFN-γ/ml)a
	Avian PPD	Bovine PPD
Nonvaccinated	1.10 ± 0.25	0.40 ± 0.12
DNA	1.09 ± 0.24	0.45 ± 0.16
DNA/BCG	1.14 ± 0.26	0.47 ± 0.11
BCG	1.12 ± 0.24	0.48 ± 0.10

^aAmount of IFN-γ in whole-blood cultures from 12 calves per group. The values are means ± standard errors of the means.