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New Approaches to HIV Prevention: Present Status, Future Hopes Willard Cates, Jr., MD, MPH Family Health International Contraceptive Technology Conference.

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Presentation on theme: "New Approaches to HIV Prevention: Present Status, Future Hopes Willard Cates, Jr., MD, MPH Family Health International Contraceptive Technology Conference."— Presentation transcript:

1 New Approaches to HIV Prevention: Present Status, Future Hopes Willard Cates, Jr., MD, MPH Family Health International Contraceptive Technology Conference March 31, 2007

2 Key Topics HIV prevention rationaleHIV prevention rationale HIV prevention approachesHIV prevention approaches Current trialsCurrent trials Future directionsFuture directions

3 HIV Prevention Research - Why Continued spread of HIVContinued spread of HIV Clear moral imperative to conduct prevention scienceClear moral imperative to conduct prevention science

4 2007 – Do the HIV Math Major success in ART access – 1.65 M on treatment, BUTMajor success in ART access – 1.65 M on treatment, BUT 4.3 M new HIV infections4.3 M new HIV infections Were losing our fight against HIVWere losing our fight against HIV

5 Prevention vs. Therapeutic Research: Contrasts Prevention Subjects are relatively healthy, asymptomatic Low morbidity and mortality Long time frame Sample sizes large Community base of research Industry support is unusual due to no profitable market Cost per trial 10 7-8 Therapeutic Subjects have defined diseases or conditions Substantial morbidity/mortality Short time frame Sample sizes modest Clinical base of research Industry support is common due to profitable market Cost per trial 10 5-6

6 Reduce High Risk Behavior Rx STDs Interventions to Prevent HIV HIV+ HIV- Newly HIV+ Rx OIs Perinatal Rx HIV Block with Barriers Circumcision Vaccine ART PREP Routes Sexual Blood Perinatal HIV+

7 Contraceptive Pregnancy Rates Oral Contraceptives Source: Trussell (2004); NCHS (2005) Percent of Women Pregnant in First Year of Use Rate during typical use Rate during perfect use Female/male sterilization Implant/Depo-Provera Spermicides Diaphragm w/spermicides Male condom IUD (TCu-380A) 010 15 2025 5 Female condom

8 HIV Prevention Tools - Infection Rates Oral Acyclovir Percent of Persons Infected after a Decade of Use Rate during typical use Rate during perfect use Male circumcision Vaccines Microbicides Diaphragm Male condom Oral ARV 0406080 20 Female condom Abstinence

9 Risk of HIV Transmission, By Consistency of Condom Use, Discordant Couples 0.9 5.1 6.5 0 1 3 5 7 AlwaysSometimesNever Source: Davis and Weller (1999) HIV Incidence/ 100 PY Consistent NonuseInconsistent

10 Male Circumcision – Biological Plausibility Inner mucosa of foreskin is rich in HIV target cells External foreskin/shaft keratinized and not vulnerable After circumcision, only vulnerable mucosa is urethral meatus Moist sub-preputial space increase HIV survival

11 Male Circumcision – 3 RCTs Orange FarmRakaiKisumu PopulationSemi-urbanRuralUrban MC Rate20%16%10% HIV Incidence1.6%1.0%1.6% Age Range18-24 yrs15-49 yrs18-24 yrs Sample size3,1284,9962,784 DMC StoppedNov. 2004Dec. 2006 Protex – ITT60%51%53% – As Rxd76%55%60%

12 Complications from Circumcision in Africa Orange Farm Trial (ages 18-24 yrs) –Complication rate of 3.8% Kisumu (ages 18-24 yrs) –Complication rate of 1.7% Bungoma, Kenya –17.5 % complication rate in medical settings –35% complication rate in traditional settings

13 Topical Microbicides – Current Products BufferGel Carraguard Pro2000 Tenofovir

14 Diaphragm RCT in Zimbabwe, S Africa Diaphragm plus lubricant gel vs. condom 4,500 participants enrolled Results expected soon

15 Female Condoms Biologic plausibility similar to male condoms If made available, lowers overall level of unprotected acts Emerging evidence on STD prevention when used consistently

16 Oral Acyclovir Prophylaxis Acquisition – HSV+, HIV- subjects – HPTN 039 – USA and global – 3,000 participants – MSM, MSW – Results expected 2007 Transmission – HSV+, HIV+ subjects – Gates – US and global – 3,600 HIV discordant couples – Results expected 2009

17 Oral ARV Pre-exposure Prophylaxis Focus for prevention trial ethics/politics Studies in multiple populations globally Testing 3 transmission routes Different drugs and regimens West Africa TDF safety data – summer 06, International AIDS Meeting

18 West Africa TDF Conclusions Daily oral use of TDF in HIV-uninfected women was not associated with increased adverse events No evidence of risk compensation Acceptability of and adherence to TDF regimen were possible Effectiveness could not be evaluated conclusively

19 ARV Treatment as Prevention Viral load importance HPTN 052 – 8 sites, 5 countries Pilot phase completed Full trial – 1,760 discordant couples

20 Contraception as HIV Prevention Willard Cates, Jr., MD, MPH Family Health International HIV Prevention Trials Conference March 29, 2007

21 Contraception is HIV Prevention Willard Cates, Jr., MD, MPH Family Health International HIV Prevention Trials Conference March 29, 2007

22 WHO Four Element PMTCT Strategy Prevention of HIV in uninfected women, especially young women Prevention of unintended pregnancies in HIV- infected women Prevention of transmission from an HIV- infected woman to her infant Support for mother and family Element 1Element 2Element 3Element 4 General Population FP & Postnatal Clinics ANC Clinics HIV Care/ Treatment

23 577,000 unintended births averted annually in HIV+ women – implications for orphanage 30% vertical transmission if no ARTs 173,000 HIV+ births prevented annually If unmet need for contraception addressed, this number could be doubled. Effect of Current Contraceptive Use by HIV+ Women Source: Reynolds, et al., 2005

24 Contraception – The BEST KEPT SECRET in HIV Prevention Effective contraception for HIV- infected women who do not wish to become pregnant –Prevents more infants becoming infected than NVP –Decreases the number of future orphans Key Question – how best to promote the SRH/HIV linkages?

25 Key Linkages Learn HIV status Promote safer sex Optimize connection between HIV/AIDS and STI services Integrate HIV/AIDS with maternal and infant health HIV/AIDS Prevention Treatment Care Support SRH and HIV: Key Linkages SRH Family Planning Maternal & infant care Management of sexually transmitted infections Management of other SRH problems Source: WHO/UNAIDS, IPPF/UNFPA (2005)

26 Future Directions Acute HIV infection 3 rd generation microbicides New formulations and combinations

27 Transmission Efficiency

28 Simultaneous Prevention Interventions in Early HIV Infection Interval PathwayIntervention BiologicART to lower viral load BehavioralIndividual counseling to promote safer behaviors SocialStructural interruption of network processes

29 Topical Microbicides – 3rd Generation Products ACID FORM VivaGel CAP TMC 120 UC-781

30 Microbicides – Regimens/Formulations Coitally – gel, film, suppository, oral Daily – gel, oral Longer Acting – vaginal ring, sponge

31 HIV Prevention - 2007 HIV prevention regaining momentum Combination of methods necessary – ABC…Z (The full alphabet) Current methods are working – when used New methods being evaluated


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