TABLE 2.

Respiratory scores and weight measurements of the three groups of pigs^a

Day p.i.b	Mean respiratory scorec for group:			Wt ratio (postinfection/pre-infection) for group:
	1	2	3	1	2	3
1	0	0	0	1.04	1.05	1.47
3	1.07 ± 0.61	0	0	1.04	1.15	1.26
5	1.75 ± 0.62	0	0	0.951	1.16	1.36
7	2.50 ± 0.71	0	0	0.899	1.16	1.18
10	3.00 ± 0.76	0	0	0.899	1.40	1.27
14	3.38 ± 0.74	0	0	0.891	1.40	1.54
21	2.00 ± 0.82	0	0	1.256	1.56	1.33
28	0.5 ± 0.71	0	0	1.35	1.40	1.64

^aGroup 1 and group 2 pigs were infected with PRRSV HuN4 and HuN4-F112, respectively. Group 3 was the control group with pigs injected with PBS.

^bThe numbers of pigs measured at each day p.i. were as follows: 16 at 0 days p.i., 16 at 1 day p.i., 14 at 3 days p.i., 12 at 5 days p.i., 10 at 7 days p.i., 8 at 10 days p.i., 6 at 14 days p.i., 4 at 21 days p.i., and 2 at 28 days p.i.

^cRespiratory scores ranged from 0 to 4 (see the text for the definition of each score).