TABLE 5.

Neutralization of SHIV-89.6P in MT-2 cells and human PBMC by sera from animals immunized with the C4/89.6P-V3 peptide

Challenge group	Animal no.a	Titerb in MT-2 cells	% Reduction in p27 in human PBMCc
SHIV-89.6P	13789	1:47	91
	15075	<1:5	51
	15475	1:26	76
	18351	1:5	45
SHIV-89.6	13947	1:23	84
	15032	1:5	67
	17071	1:22	57

^aAnimals were inoculated with the C4/89.6P-V3 peptide immunogen. Serum samples were obtained on the day of challenge (2 weeks after the sixth inoculation). 

^bTiters are the serum dilutions at which 50% of cells were protected from virus-induced killing. 

^cSerum samples were tested at a 1:2 dilution in triplicate. The percent reduction in p27 synthesis is calculated relative to the amount of p27 produced in the presence of prebleed serum from animal 13718 (3,407 pg/ml).