Table 1.

In vitro and vivo evaluation of toxin neutralizing antibody following immunization of mice with DNA vaccine

Vaccinea	Dose	Toxin neutralizing titer ED50 b		Toxin challenge surivalc
		Anti-TcdA	Anti-TcdB	TcdA	TcdB	TcdA + B
p	50 μg	0	0	0	0	0
pTA		100 ± 30.15	0	90 %	0	0
pTB		0	1133 ± 327.9	10 %	100 %	0
pTAB		140 ± 27.63	1200 ± 294.4	100 %	100 %	80 %

^aMice received three immunizations (day 0, day 14 and day 28)

^bSera were obtained 7 days following the third immunization. The data are expressed as geometric mean toxin neutralizing titer ± Standard Error of the Mean (SEM) of 10 mice per group

^cBalb/C mice (10 mice/group) were challenged i.p with 50 ng TcdA or/and 25 ng TcdB 10 days following the second boost of DNA immunization