TABLE 6.

Longitudinal analysis of plasma-neutralizing responses and HIV-1 neutralization sensitivities for selected members of the SBBC^a

Virus	Plasma	Yr postinfection	ID50	ID80
HIV-1D36III	D36III	14.5	668	<100
	D36VIII	16.4	298	<100
	D36IX	17.0	NT	NT
	D36XI	18.1	132	<100
	D36XVI	19.8	813	<100
HIV-1D36IX	D36III	14.5	319	<100
	D36VIII	16.4	<100	<100
	D36IX	17.0	597	<100
	D36XI	18.1	<100	<100
	D36XVI	19.8	395	<100
HIV-1D36XI	D36III	14.5	158	<100
	D36VIII	16.4	<100	<100
	D36IX	17.0	NT	NT
	D36XI	18.1	<100	<100
	D36XVI	19.8	245	<100
HIV-1C18(2)	C18(2)	9.8	>3200	531
	C18(4)	10.5	2886	140
HIV-1C18(4)	C18(2)	9.8	>3200	262
	C18(4)	10.5	2144	<100
HIV-1C54IV	C54IV	10.9	>3200	<100
	C54XV	15.6	1173	<100
HIV-1C54XV	C54IV	10.9	640	<100
	C54XV	15.6	708	<100
HIV-1C64IV	C64IV	12.9	<25	<25
	C64XII	16.0	<25	<25
	C64XVII	18.3	<25	<25
HIV-1C98IV	C98II	12.8	255	<100
	C98IV	14.0	<100	<100
	C98XII	16.7	103	<100
	C98XIV	17.8	1311	<100
	C98XVI	18.8	556	151
HIV-1C98XIV	C98II	12.8	699	<100
	C98IV	14.0	796	<100
	C98XII	16.7	<100	<100
	C98XIV	17.8	1061	<100
	C98XVI	18.8	1193	413

^aSequential plasma samples from SBBC members from whom HIV-1 had been isolated (D36, C18, C54, C64, and C98) were tested for neutralization of sequential virus isolates from the same individual. Plasma samples were tested at twofold dilutions from 1:100 to 1:3,200, except for C64 plasma (1:25 to 1:800). Replication was measured by cell-free RT activity, except for HIV-1_C54IV and HIV-1_C54XV, which were analyzed for supernatant p24 antigen production. Fifty percent and 80% inhibitory dilutions (ID₅₀ and ID₈₀) are shown as the reciprocal of the plasma dilution calculated to cause 50% or 80% neutralization. Boldface, subject was undergoing antiretroviral therapy at the time of sampling.