TABLE 3.

Postchallenge neutralizing antibody titers

Wk	50% Neutralization titer for strain and macaque no.a:
	Mm 12-94b			Mm 169-84b			Mm 245-91b			Mm 415-90b			Mm 95-00b			Mm 232-95b
	239	316	251LA	239	316	251LA	239	316	251LA	239	316	251LA	239	316	251LA	239	316	251LA
0	—	30	80	—	80	120	—	40	60	—	60	80	—	—	—	—	—	—
2	—	480	1,920	—	—	160	—	120	240	—	80	240	—	—	—	—	—	—
4	—	NT	7,680	—	NT	5,120	—	NT	5,120	—	NT	7,680	—	NT	160	—	NT	160
20	—	NT	10,240	—	NT	7,680	—	NT	15,360	20	NT	1,920	60	NT	5,120	20	NT	3,840

^aNeutralizing antibody titers indicate the reciprocal of the plasma dilution that reduced SIV infection of CEMx174 cells containing a Tat-inducible SEAP reporter construct by 50%. Antibody neutralization was tested against SIV_mac239 (239), SIV_mac316 (316), and a lab-adapted strain of SIV_mac251 (251_LA). Samples that were negative for virus neutralization at the lowest dilution tested (<1:20) are indicate by a dash (—). Time points that were not tested for neutralization of SIV_mac316 are indicated by NT.

^bMm 12-94, Mm 169-84, Mm 245-91, and Mm 415-90 were immunized with three doses of scSIV_mac239Nef^sff and scSIV_mac316Nef^sff. Mm 95-00 and Mm 232-95 are unvaccinated, Mamu-A*01⁺ control animals. All six animals were challenged intravenously with SIV_mac239 6 weeks after the third scSIV immunization.