Anti-idiotypic antibodies reduce efficacy of the attenuated vaccine against highly pathogenic PRRSV challenge

BMC Veterinary Research

Table 3 Neutralizing antibodies detected from sera collected on different DPIs and DPCs

DPIs/DPCs	Titers of neutralizing antibodies from six groups of piglets¹
	1	2	3	4	5	6
DPIs
0	0 (6) ²	0 (6)	0 (6)	0 (6)	0 (6)	0 (6)
7	0 (6)	0 (6)	0 (6)	0 (6)	0 (6)	0 (6)
14	0 (6)	0 (6)	0 (6)	0 (6)	0 (6)	0 (6)
21	2.3 (6)	2.7 (6)	0 (6)	0 (6)	0 (6)	0 (6)
28	3.3 (6)	3.3 (6)	0(6)	0 (6)	0 (6)	0 (6)
35	3.3 (6)	3.7 (6)	4.7 (6)	5.3 (6)	0 (6)	0 (6)
DPCs
0	3.7 (6)	3.7 (6)	6 (6)	6.3 (6)	0 (6)	0 (6)
3	2.7 (6)	3.3 (6)	5.3 (6)	5.3 (6)	0 (6)	0 (6)
7	3.3 (6)	3.3 (6)	5.3 (6)	6 (6)	0 (6)	0 (6)
10	3.3 (6)	3.3 (6)	6.7 (6)	8 (6)	0 (6)	0 (6)
14	3.7 (6)	4.7 (6)	8.7 (6)	10.1(6)	5.3 (6)	0 (6)
21	6 (2)	6.7 (3)	10.7 (3)	13.3 (3)	12 (2)	0 (3)

¹Neutralizing antibodies were detected to evaluate the ability of antibodies against Mab2-5G2 and aAb2s to neutralize PRRSV infection of Marc-145 cells. Briefly, a 2-fold diluted serum sample and a titer of 100 TCID₅₀/mL was incubated for 1 h at 37°C and was transferred to a 96-well plate containing a Marc-145 cell monolayer. Neutralizing antibody titers were defined as the mean of reciprocal of the highest dilution of sera that inhibited 50% CPE.
²Each number represents the mean dilution of neutralizing antibody titers generated from six groups of piglets on different DPIs/DPCs. The numbers in parentheses were the numbers of piglets measured on different DPIs/DPCs.

ISSN: 1746-6148