TABLE 2.

Peak ELISA and IIIb-neutralizing titers^a

Group	Rabbit	Anti-Env ELISA titers (μg of IgG/ml of serum)			IIIb-neutralizing titers
		DNA	rgp160 × 1	rgp160 × 2	DNA	rgp160 × 1	rgp160 × 2
Env	R104	0.3 ± 0.1	65 ± 12	1,150 ± 202	<20	NDb	1,198
	R105	0.4 ± 0.1	105 ± 14	1,693 ± 342	<20	287	2,425
	R106	0.5 ± 0.1	70 ± 28	879 ± 263	<20	199	1,963
		0.4	78	1,196		243	1,786
Env++	R107	1 ± 0.2	101 ± 30	1,017 ± 331	<20	411	546
	R108	2 ± 0.8	81 ± 14	678 ± 219	<20	500	2,560
	R109	4 ± 0.2	102 ± 34	762 ± 206	48	95	830
		0.9	94	807		269	1,050
dpol	R110	2 ± 0.6	187 ± 29	864 ± 212	105	291	18,369
	R111	0.6 ± 0.1	50 ± 6	420 ± 100	<20	47	2,829
	R112	0.8 ± 0.1	133 ± 33	568 ± 137	<20	1,487	5,318
		0.8	108	590		272	6,516
dpol++	R113	0.4 ± 0.1	131	674 ± 356	<20	953	1,488
	R114	3 ± 0.6	87 ± 12	393 ± 102	108	765	861
	R115	2 ± 0.1	107 ± 19	714 ± 296	<20	228	886
		1	107	574		550	1,043
rgp160 only	R126		8 ± 2	176 ± 59		61	869
	R127		28 ± 9	221 ± 58		102	1,174
	R128		18 ± 4	229 ± 85		131	741
			16	207		93	911

^aPeak DNA-elicited titers were determined 2 weeks after the third DNA priming (DNA), while boosted titers were determined 4 weeks after each protein boost (rgp160 × 1 and rgp160 × 2, first and second protein boosts with rgp160, respectively). All ELISAs were performed three times, and titers are expressed as arithmetic means ± standard deviations. IIIb-neutralizing titers (50% neutralization) of the same serum samples were determined on MT-2 cells by using a cell viability assay. Values in boldface type are GMTs. ELISA and neutralizing titers were determined either 2 or 4 weeks after the final DNA immunization or each protein immunization. 

^bND, this value was not determined.