TABLE 1.

Summary of small-scale SHIV 375 Env challenge stocks

SHIV variant by stock	PBMC typea	Viral load (RNA copies/ml)	SIV p27 levels in PBMC (ng/ml)	Infectivity titer (TCID50/ml)b
162p3
Parental	Rhesus	3.48 × 108	14.51	1.75 × 106
S/WTc	Rhesus	1.07 × 109	35.65	1.67 × 108
M	Rhesus	6.24 × 108	23.05	1.95 × 107
H	Rhesus	1.00 × 109	22.18	1.95 × 107
W	Rhesus	5.89 × 108	18.82	1.83 × 104
Y	Rhesus	7.33 × 108	20.01	7.81 × 105
F	Rhesus	8.53 × 108	37.63	3.91 × 106
AE16
Parental	Human	2.10 × 109	102.90	1.00 × 104
H/WT	Human	6.13 × 109	362.20	1.95 × 107
M	Human	9.43 × 108	32.70	3.49 × 105
S	Human	1.76 × 109	45.10	3.13 × 104
W	Human	6.97 × 108	36.80	4.57 × 105
Y	Human	2.84 × 109	114.95	3.91 × 106
F	Human	8.33 × 108	30.25	1.75 × 106
325c
Parental	Human	2.19 × 109	91.67	4.57 × 105
S/WT	Human	3.76 × 109	45.06	4.88 × 108
M	Human	2.38 × 109	67.32	>4.88 × 108
H	Human	3.74 × 109	93.05	>4.88 × 108
W	Human	3.19 × 109	78.23	>4.88 × 108
Y	Human	3.78 × 109	37.4	5.71 × 107
F	Human	3.19 × 109	49.52	5.71 × 107

^aPBMC type utilized for SHIV generation.

^bInfectivity in TZM.bl cells (TCID₅₀/ml). These values were established for the virus stocks after 12–15 days in culture with PBMCs.

^cWT, wild type.