TABLE 1.

Flow cytometric analysis of responses to B. abortus strain 19 after initial and booster vaccination^a

Time postvaccination and animal group	Mean no. of proliferating cells/10,000 PBMC ± SEMb
	Total	CD4+	CD8+	γδTCR+	IgM+
14 wk after initial vaccination
Controls	893 ± 407	126 ± 46	25 ± 11	22 ± 15	881 ± 174
RB51 vaccinates	1,833 ± 579*	449 ± 351	19 ± 15	335 ± 311	1,927 ± 432*
S19 vaccinates	1,262 ± 467	64 ± 42	64 ± 64	59 ± 59	1,942 ± 607*
22 wk after initial vaccination
Controls	367 ± 367	353 ± 325	76 ± 42	38 ± 27	273 ± 184
RB51 vaccinates	2,161 ± 1,187*	1,354 ± 384*	381 ± 101*	89 ± 89	1,277 ± 333*
S19 vaccinates	2,063 ± 405*	2,282 ± 245*	529 ± 253	11 ± 93	1,873 ± 212*
12 wk after booster vaccination
Controls	0 ± 0	404 ± 322	88 ± 34	28 ± 42	141 ± 30
RB51 vaccinates	0 ± 0	808 ± 488	232 ± 121	0 ± 0	467 ± 196
S19 vaccinates	1,000 ± 541	691 ± 303	306 ± 134	24 ± 41	637 ± 266

^aPKH-67-labeled PBMC from elk vaccinated s.c. with saline (control), SRB51, or S19 (n = seven animals/treatment) and booster vaccinated 65 weeks later were incubated with 10⁸ CFU of gamma-irradiated B. abortus strain 19 at 37°C and 5% CO₂ for 7 days, labeled with monoclonal antibodies, and analyzed in a flow cytometer.

^bMeans within a sampling time with an asterisk are significantly different (P < 0.05) from means of controls labeled with the same monoclonal antibody.