Table 2.

Model estimates of the annual probability of a woman acquiring HIV in one year, assuming that a microbicide reduces the per sex act risk of HIV acquisition by 60%, for different patterns of product use and assumptions about the likelihood that her sexual partner is HIV-infected

	Percent of women becoming HIV-infected in one year
	Probability partner HIV-infected
	100	75	50	25	1
No product use	21.0	15.7	10.5	5.2	0.2
20% condom use, no microbicide use	17.7	13.3	8.9	4.4	0.2
0% condom use, 75% microbicide use	12.9	9.6	6.4	3.2	0.1
50% condom use, no microbicide use	12.4	9.3	6.2	3.1	0.1
20% condom use, 75% microbicide use	10.8	8.1	5.4	2.7	0.1
50% condom, 75% microbicide use	7.5	5.7	3.8	1.9	0.1
Assumes 1 sexual partner, 100 sex acts per year, 5% of HIV-infected partners have increased risk of transmission due to high viremia, condoms reduce per sex act transmission risk by 95%, male-to -female HIV transmission probability 0.193%.

More information on the modeling behind this table is provided in Appendix 1.