Table 1. Study subjects, sequence details and natural vpu variation.

Subject	Time (yrs)1	Viral load2	CD4 counts (per ml)	Sequence number3	Unique sequences4		Genetic distance (substitution/site)
					NT	AA	NT	AA
							Mean	Mean	Max
RP 1	1.2	32,280	186	36	18	14	0.007	0.011	0.051
RP 2	1.0	106,070	442	35	22	14	0.032	0.020	0.051
RP 3	2.0	109,736	166	36	28	22	0.018	0.033	0.080
RP 4	2.0	40,403	147	33	21	13	0.013	0.023	0.079
RP 5	1.1	7,095	770	34	13	10	0.007	0.019	0.065
NP 1	1.6	63,265	636	33	17	9	0.010	0.016	0.058
	3.5	27,610	498	43	21	13	0.015	0.027	0.078
NP 2	2.0	16,221	513	34	19	14	0.010	0.022	0.063
	4.2	62,022	370	33	25	18	0.019	0.029	0.077
NP 3	0	52,367	750	41	12	6	0.005	0.004	0.044
	1.6	55,603	553	38	14	10	0.006	0.015	0.060
	3.9	266,082	127	33	18	12	0.017	0.030	0.077
NP 4	4.9	303,776	309	30	14	8	0.009	0.015	0.051
LTNP 1	1.1	28,653	429	32	20	18	0.022	0.058	0.168
	4.4	106,333	758	32	18	13	0.026	0.060	0.179
	10.4	82,071	374	41	27	14	0.039	0.073	0.224
LTNP 2	1.2	8,096	672	31	17	7	0.012	0.008	0.067
	3.6	31,766	864	35	21	8	0.020	0.019	0.064
LTNP 3	1.2	6,997	425	29	12	10	0.013	0.035	0.135
	4.5	29,229	428	30	18	15	0.029	0.058	0.135
LTNP 4	0	448,694	596	31	4	2	0.001	0.001	0.012
	1.1	10,268	276	31	9	5	0.003	0.004	0.034
	3.5	12,250	296	33	15	7	0.007	0.008	0.051
LTNP 5	1.1	54,053	986	36	29	20	0.017	0.043	0.181
	3.6	30,343	504	31	24	22	0.020	0.045	0.107

¹ The time point of the plasma sample, in years post-seroconversion.

² Viral RNA copies/ml peripheral blood.

³ The total number of vpu sequences obtained per sample by single genome amplification.

⁴ Unique sequences represent the number of alleles per sample after stripping of duplicates.