TABLE 1.

HIV-1-specific antibody titers in sera from vaccinees and infected individuals

Seraa	Neutralizing antibody titer to HIV-1W61Dc	Antibody binding titers tod:
		V3W61D	rgp120W61D	sCD4/ rgp120W61D BS
Vaccinees (n = 9)
Median	<10	800	12,800	80
Range	<10	800–6,400	6,400–25,600	40–320
W61D-Nonneutral-izing (n = 19)
Median	<10	400	25,600	160
Range	<10	<100–1,600	3,200–102,400	<20–640
P valueb	NSe	0.0104	NS	NS
W61D-Neutral-izing (n = 9)
Median	40	100	25,600	160
Range	40–320	<100–400	3,200–51,200	80–640
P value	0.0004	0.0004	NS	NS

^aSera from rgp120_W61D-immunized individuals and HIV-1-infected individuals. The latter are subdivided as W61D-nonneutralizing or W61D-neutralizing, according to the neutralization of the PBMC-derived isolate, HIV-1_W61D, when assayed on MT2 cells. 

^bP values, generated by the nonparametric unpaired Mann-Whitney U test, refer to differences between the vaccinee sera and the appropriate neutralization group. 

^cTiters are expressed as the reciprocal of the highest dilution of serum which inhibited the formation of syncytia by 90% relative to that of controls. 

^dData are presented as the median and range of end point antibody binding titers to the V3_W61D loop and to monomeric rgp120 derived from HIV-1_W61D and 50% inhibition titers to the sCD4 binding site on monomeric rgp120_W61D. 

^eNS, P value of >0.05.