Table 1.

Protection conferred to BALB/c mice immunized with the pV267 and pV270 DNA vaccines when challenged with the pathogenic B. abortus 2308 strain.

Experimental group (n = 5)	Log10 CFU of Brucella abortus 2308 per spleen (means ± SD)	Log10 units of protectiona
PBS	5.88 ± 0.06	0
pVAX1	5.88 ± 0.18	0
pV267	5.25 ± 0.15	0.63
pV270	4.97 ± 0.26	0.91*
RB51 vaccinal strain	4.01 ± 0.21	1.8***

^aunits of protection represent the difference between log₁₀ CFU values of the PBS control group and the log₁₀ CFU values of the immunized group. All animals were challenged with B. abortus 2308 and bacterial counts were assessed at day 15.

^*P < 0.05

and

^***P < 0.001.