TABLE 4.

Virus neutralization of in vitro- and in vivo-generated chimeric viruses derived from C1.1.1 and CoBrB ⁴⁷⁶S

Virus	Neutralization of SK6-generated virusa			Neutralization of in vivo-generated virusa
	V4	V6	PabR-RI	V4	V6	PabR-RI H
CoBrB 476S	4.0	0.8	2.0	5.0	0.0	1.5
CoBrB 476S/C1.1.1 (E2-p7-pNS2-3′)	3.5	2.6	3.4	4.8	2.5	5.7
CoBrB/C1.1.1 (Npro′-C-Erns-E1)	4.8	0.3	1.5	4.8	0.3	0.8
C1.1.1/CoBrB	5.7	3.0	3.3	NDb	ND	ND

^aNeutralization of in vitro (produced on SK6)- or in vivo-generated chimeric viruses derived from C1.1.1 and CoBrB ⁴⁷⁶S. Blood samples from animals 5012 (CoBrB ⁴⁷⁶S), 5016 [CoBrB ⁴⁷⁶S/C1.1.1 (E2-p7-pNS2-3′)], and 5024 [CoBrB/C1.1.1 (N^pro′-C-E^rns-E1)] were collected, and the titers of virus from the blood samples were determined on SK6 cells with or without neutralizing MAbs or PAbs. The values represent the log TCID₅₀ per milliliter reduction of CSFV titers due to the presence of MAbs or PAbs. Neutralizing MAbs and PAbs are as follows: MAb V4 (directed against the conserved A domain of E2), MAb V6 (directed against domain B of E2), and a serum sample from a CoBrB Ems^R-RI E2^H-infected pig (Pab^{R-RI H}).

^bND, not done because the virus titers in blood samples from pigs infected with this virus were too low.