Vaginal gels were not effective at stopping HIV transmission, despite the foundation's optimism that they could prevent infection.

TRUE: major clinical trials of vaginal microbicide gels against HIV completed before February 2020 (for example VOICE, FACTS 001, and the confirmatory follow-ups to CAPRISA 004 with tenofovir gel) failed to show meaningful efficacy in preventing HIV transmission, and the Gates Foundation had funded or backed these gels. MOSTLY TRUE: the gels failed overall in the decisive trials, but one trial showed partial or adherence-dependent efficacy (for example CAPRISA 004's roughly 39% reduction) that the blanket statement skips over. MIXED: the trial evidence was genuinely split, with some gels showing efficacy that regulators or guidelines accepted. MOSTLY FALSE: a vaginal gel was shown effective and adopted, with failures limited to some products. FALSE: vaginal gels were demonstrated effective at stopping HIV transmission.

Set before the research began.

1. E1 New tenofovir gel study shows no effect on HIV prevention: Lower than expected gel use impact FACTS trial results CAPRISA (Centre for the AIDS Programme of Research in South Africa) · 24 February 2015

   “The FACTS 001 trial involving 2059 South African women showed no overall HIV prevention benefit of the gel. However, a sub-group analysis based on gel use confirmed by tenofovir detection in genital fluid, showed a 52% reduction in HIV infection.”

2. E2 New tenofovir gel study shows no effect on HIV prevention: Lower than expected gel use impact FACTS trial results CAPRISA (Centre for the AIDS Programme of Research in South Africa) · 24 February 2015

   “The CAPRISA study had reported in 2010 that tenofovir, applied as a gel before and after sex, reduced HIV infection by 39% overall and by 54% in women who used the gel consistently.”

3. E3 New tenofovir gel study shows no effect on HIV prevention: Lower than expected gel use impact FACTS trial results CAPRISA (Centre for the AIDS Programme of Research in South Africa) · 24 February 2015

   “The VOICE study recently reported no impact of tenofovir gel on HIV prevention because many of the women in that trial did not adhere to the daily dosing regimen.”

CAPRISA's 2015 release reports that the FACTS 001 trial of tenofovir gel showed no overall HIV prevention benefit (E1). It also says the VOICE trial found the gel had no effect, which it put down to poor adherence (E3). The same release notes that CAPRISA 004 had reported a 39% overall reduction in 2010, and E1 records a 52% reduction among women whose gel use was confirmed. The blanket statement leaves out these partial and adherence-dependent results (E2, E1). None of the evidence covers the Gates Foundation's funding or optimism, but the main claim that the gels failed in the decisive trials is supported.