Table 1.

Participant characteristics stratified by age and sex among the 801 participants enrolled in HVTN 503/Phambili, 2007.

	Females 18-20 (n=99) %	Females 21-35 (n=261) %	p-value	Males 18-20 (n=139) %	Males 21-35 (n=302) %	p-value	Overall p-value 18-20 vs. 21-35
Race			0.42			0.22	0.28
Black	99.0	98.8		100.0	98.7
Other	1.0	1.2		0	1.3
Study site			0.31			<0.001	<0.001
Soweto	40.6	40.2		47.5	31.5
Cape Town	25.7	29.0		4.3	20.5
KOSH	26.7	19.3		37.4	29.8
CAPRISA	5.9	7.0		4.3	7.6
Medunsa	1.0	4.6		6.5	10.6
Adenovirus 5 titer			0.15			0.64	0.56
<200	37.6	46.0		46.8	44.4
>200	63.4	54.0		53.2	55.6
Risk behaviors in previous 6 months:
Number of sexual partners (MEAN)	1.3	1.1	0.001	2.5	2.2	0.21	0.05
Unprotected vaginal sex (YES VS. NO)	50.5	57.1	0.25	45.7	63.5	<0.001	<0.001
Drinking or drugs with sex (YES VS. NO)	13.9	10.0	0.30	35.3	41.4	0.22	0.58
Casual or anonymous partner (YES VS. NO)	13.9	10.0	0.30	48.2	47.0	0.82	0.48
Exchanged sex for money or gifts (YES VS. NO)	1.0	1.2	0.42	7.2	4.6	0.27	0.33
Sexually transmitted infection (self report) (YES VS. NO)	3.0	6.2	0.11	2.9	7.6	0.03	0.02
Heavy drinking (>5 drinks/day) (MEAN NUMBER OF DAYS)	1.4	1.4	0.99	6.5	7.0	0.71	0.71
Believe vaccine is:			0.86			0.87	0.97
Very effective	5.9	5.0		7.2	7.0
Somewhat effective	19.8	17.8		19.4	22.9
Not effective	2.0	1.5		2.2	2.0
I don't know	72.3	75.7		71.2	68.2
Prior to unblinding, I think I received:			0.97			0.07	0.28
Vaccine	31.5	32.9		51.6	42.2
Placebo	19.1	19.0		20.5	17.5
I don't know	49.4	48.2		27.9	40.2
Participation in trial had beneficial impact on life	69.0	67.7	0.92	83.8	72.7	0.04	0.14
Social harm from study involvement:			0.50			0.22	0.20
Minimal disturbance	5.0	8.4		0.7	3.1
Moderate/Major disturbance	2.0	1.2		0.7	2.0
Loss to follow-up during study	21.2	19.8	0.76	22.6	28.3	0.21	0.43
Adverse event:
Related to study product	1.0	8.5	0.004	7.9	7.3	0.82	0.14