Table 7.

Frequency of detection of challenge virus in different vaccine groups

Group	Post-challenge samples (no. positive/total)
	Day 2		Day 4		Day6		Day9
	Oa	Cb	O	C	O	C	O	C
Oil- TC/1	12/12c	10/12	4/12	4/12	2/12	1/12	0	0
Oil-Las	12/12	11/12	10/12	8/12	7/10	6/10	3/10	2/10
Live-Las	12/12	10/12	9/12	8/12	5/10	4/10	2/9	2/9
Oil- TC/1plus Live-Las	12/12	10/12	3/12*	3/12*	1/12	0	0	0
Oil-Las plus Live-Las	12/12	11/12	8/12	7/12	5/12	3/12	2/11	1/11
Un-inoculated control	12/12	12/12	12/12	12/12	NSd	NS	NS	NS

^aOropharyngeal swabs. ^bCloacal swabs. ^cThe number in front of the slash represents the number of animals, which had detectable viral genome RNA; the number behind the slash stands for the total number of animals in this group. ^dNo survivors. *Significant difference (P < 0.05) among immunized groups with the column