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Continued Follow-Up of Phambili Phase 2b Randomized HIV-1 Vaccine Trial Participants Supports Increased HIV-1 Acquisition among Vaccinated Men.
- Source :
-
PloS one [PLoS One] 2015 Sep 14; Vol. 10 (9), pp. e0137666. Date of Electronic Publication: 2015 Sep 14 (Print Publication: 2015). - Publication Year :
- 2015
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Abstract
- Background: The Phase 2b double-blinded, randomized Phambili/HVTN 503 trial evaluated safety and efficacy of the MRK Ad5 gag/pol/nef subtype B HIV-1 preventive vaccine vs placebo in sexually active HIV-1 seronegative participants in South Africa. Enrollment and vaccinations stopped and participants were unblinded but continued follow-up when the Step study evaluating the same vaccine in the Americas, Caribbean, and Australia was unblinded for non-efficacy. Final Phambili analyses found more HIV-1 infections amongst vaccine than placebo recipients, impelling the HVTN 503-S recall study.<br />Methods: HVTN 503-S sought to enroll all 695 HIV-1 uninfected Phambili participants, provide HIV testing, risk reduction counseling, physical examination, risk behavior assessment and treatment assignment recall. After adding HVTN 503-S data, HIV-1 infection hazard ratios (HR vaccine vs. placebo) were estimated by Cox models.<br />Results: Of the 695 eligible, 465 (67%) enrolled with 230 from the vaccine group and 235 from the placebo group. 38% of the 184 Phambili dropouts were enrolled. Enrollment did not differ by treatment group, gender, or baseline HSV-2. With the additional 1286 person years of 503-S follow-up, the estimated HR over Phambili and HVTN 503-S follow-up was 1.52 (95% CI 1.08-2.15, p = 0.02, 82 vaccine/54 placebo infections). The HR was significant for men (HR = 2.75, 95% CI 1.49, 5.06, p = 0.001) but not for women (HR = 1.12, 95% CI 0.73, 1.72, p = 0.62).<br />Conclusion: The additional follow-up from HVTN 503-S supported the Phambili finding of increased HIV-1 acquisition among vaccinated men and strengthened the evidence of lack of vaccine effect among women.<br />Trial Registration: clinicaltrials.gov NCT00413725 SA National Health Research Database DOH-27-0207-1539.
- Subjects :
- AIDS Vaccines adverse effects
AIDS Vaccines immunology
Double-Blind Method
Female
Follow-Up Studies
HIV Infections immunology
HIV Infections prevention & control
Humans
Male
Proportional Hazards Models
Risk Factors
South Africa
Treatment Outcome
AIDS Vaccines administration & dosage
HIV Infections epidemiology
Subjects
Details
- Language :
- English
- ISSN :
- 1932-6203
- Volume :
- 10
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- PloS one
- Publication Type :
- Academic Journal
- Accession number :
- 26368824
- Full Text :
- https://doi.org/10.1371/journal.pone.0137666