Table 2.

Antigenicity of HBsAg with second-loop deletion of α determinant

Groups	HBsAg titer by IMx S/CO value	Anti-HBs responses in DNA immunization
		Positive rate	mIU/L (GMT ± SE)
Empty control	-	0/5	-
pcDNA3	-	0/5	-
pHB	1 589 ± 234.5b	6/10	27.60 ± 17.3c
pHB-SD	106 ± 26.8	2/10	4.56 ± 3.52

S/CO: the ratio of sample against cut off value. GMT: geomet-ric mean titer.

^bP < 0.01, t = 5.02 vs groups of pHB-SD;

^cP = 0.02, t = 2.7 vs groups of pHB-SD.