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www.icad-cisd.com. New Prevention Technologies Workshop Module 1: Basic definitions. Objectives . This workshop will: Increase the capacity of media representatives to report on NPT trials with accuracy and sensitivity
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www.icad-cisd.com New Prevention Technologies Workshop Module 1: Basic definitions
Objectives This workshop will: Increase the capacity of media representatives to report on NPT trials with accuracy and sensitivity Build skills amongst community-based organizations to critically analyze media discourse about HIV prevention trials Increase the capacity of community representatives to understand and communicate NPT trial results effectively
Warm-Up Exercise • Please read the articles that have been provided to you. They all report on the same trial results. Discuss Questions: • What is the tone of each article? (Optimistic? Pessimistic?) • What conclusion do you come to after reading each article? • What information do you feel is missing?
Imagine a full spectrum of interventions Rights-focused behaviour change Voluntary counselling & testing Sexually transmitted infection screening and treatment Male medical circumcision Preventative vaccines Pre-exposure prophylaxis (PrEP) • Male & Female condoms and lubricant • Treatment to prevent vertical transmission (PMTCT) • Clean injecting equipment • Post-exposure prophylaxis (PEP) • Vaginal & rectal microbicides • Cervical barriers • Antiretroviral treatment • Treatment for opportunistic infections • Basic care/nutrition • Prevention for positives • Education and rights-focused behaviour change • Therapeutic vaccines • Functional cures
Which NPTs? • Vaccines? • PrEP? • Microbicides? • Medical male circumcision? • Female condoms? • Treatment-as-prevention?
Medical male circumcision • 3 studies conducted: South Africa, Uganda, Kenya • Trials showed: circumcised men about 60% less likely to acquire HIV through unprotected vaginal intercourse • WHO published recommendation based on study results
Medical male circumcision • 60% risk reduction for HIV-negative circumcised men during unprotected vaginal intercourse with HIV+ woman • Trials did not show reduction in transmission risk from circumcised HIV+ man to HIV-negative woman • In fact, one trial showed opposite trend: increased risk for wives of circumcised HIV+ husband; probably due to resuming sex too soon after circumcision • Trials did not provide information on effect of circumcision on HIV transmission during anal sex—for either women or men
Challenges with Male Circumcision • Public messages must be communicated very clearly: reduces but does not eliminate men’s HIV risk • Need to educate about the difference between FGC and male circumcision • “Potential harmful outcomes”: condom substitution, surgical complications, inadequate healing time • Religious and cultural meanings of circumcision • Ethics of promoting circumcision for infant boys
Female Condoms • a thin pouch that a woman can insert in her vagina before sex to prevent pregnancy and sexually transmitted infections (STIs), including HIV • FC1: Polyurethane; FC2: nitrile rubber (less noisy, cheaper than FC1) • the only proven, female-initiated method of HIV prevention currently on the market • can be used vaginally or anally • same efficacy as male condoms for STI prevention and contraception Or “the internal condom”
Challenges with Female Condoms Almost all (99.6%) condoms distributed globally are male condoms. Only a tiny fraction of women worldwide have access to female condoms. Why? • High price: US$0.60 vs. US$0.04 for male condom • Perceived and real acceptability issues: cumbersome, hard to use, partners do not like them, taboos around female sexuality • Not enough donor and policy-maker support: low interest among some major donors and governments • Discomfort among “gatekeepers”: health care providers and HIV and AIDS programme implementers
ARV-based prevention options Preventing vertical transmission (PMTCT+) PrEP Treatment of HIV+partner Vaginal microbicides (rings) Vaginal microbicides (gels) and rectal microbicides PEP
HIV prevention Not ARV-based ARV based • Male & female condoms • Circumcision • Clean injecting equipment • Vaccines • VCT • Vaginal and rectal microbicides • Preventingverticaltransmission • PEP • PrEP • Treatment for HIV+ partner
Comparing ARV-based prevention methods Drugs used Deliveryformats Frequency of use
Why test ARVs to prevent HIV? • ARVs already are used to prevent vertical transmission (or PMTCT) • PEP already is used to prevent infection after medical accidents or rape • Monkeys that get ARVs prior to exposure are less likely to be infected with “monkey forms” of HIV
Treatment as prevention • Can it work at population level? • Increased testing = more knowledge of status = less risk-taking • Increased testing = more HIV+ people on treatment = less virus • Less risk-taking + less virus = less transmission? • HIV+ people taking ARVs regularly • Does it work at individual level? • Treatment = less virus = less transmission
microbicides VIDEO
What is a microbicide? A suppository or a gel applied with an applicator before sex A vaginal ring that stays in place for up to a month
We need microbicides that: • Are both contraceptive and not contraceptive • Help reduce the risk of getting other sexually transmitted infections • Are inexpensive and easily available • Can be used without a partner’s active cooperation • Can be used vaginally or rectally • Can be used by HIV+ people (products not based on ARVs)
Why would HIV+ people want microbicides? • To reduce the risk of co-infection with other HIV strains. • To reduce the risk of other sexually transmitted infections, and yeast and bladder infections • To allow conception whilst protecting partner
1. Boost vagina’s natural defences 2. Surfactants * 5. Future possibility 4. Stop replication 3. Block binding *STDs: sexually transmitted diseases
Comparing ARV-based and non-ARV-based microbicides • More potent against HIV • May be long lasting • Not contraceptive • Could work against HIV and other sexually transmitted infections • Could be contraceptive • May be more toxic • May cause resistance • Unlikely to protect against other sexually transmitted infections • May be less potent against HIV • Must be used at time of sex
Pre-exposure prophylaxis (PrEP) For example: • Taking pills to prevent malaria when you travel • Using hormonal contraceptives (injections or pills) to prevent pregnancy • Taking pills to avoid pneumonia, if you are at risk Experimental HIV prevention strategy that would use ARVs to protect HIV-negative people from HIV infection Taking medicine to prevent rather than to treat a disease or condition.
What makes a drug a good candidate for PrEP? Now being tested: tenofovir (Viread) Truvada(tenofovir+emtricitabine combined) • Easy to use: Only one pill required per day (maybe less) • Safe: Few side effects in HIV-positive people • Powerful: Stays in the bloodstream a long time • Unique resistance profiles: If resistance develops, other treatment options still exist
Safety concerns? • Safety is a critical issue for PrEP use • Look carefully at people with pre-existing conditions: hepatitis B and C, kidney problems, bone density • Pregnancy, post-menopause (osteoporosis), adolescents (bone formation) • Look carefully at drug clearance in people with low body weight, including women and Asians
Drug resistance • More likely if taking only one drug (or one type of ARV) • Can still become HIV+ using ARV-based prevention • Use by people who don’t know they are HIV+ might lead to resistance? • Options for treatment may be more limited, might pass on resistant virus • Unanswered questions at this point
Think of weeds in a garden • To stop the big weeds: • Take away the first weed killer • Introduce other weed killers that stop all weeds – big and small If you use weed killer: • Some weeds die • Others thrive, grow bigger, and take over • The weed killer accidentally helps resistant weeds – it takes away all their competition Concept for this slide: Jeanne Marrazzo, MD and John Mellors, MD, MTN
Next steps for science • Gather more data on how PrEP works across populations • Address safety concerns through current trials and further research • Learn how to monitor widespread resistance • Study intermittent use: for example, taking it only when you expect to have sex. • Find out about impact on pregnancy and breast feeding • Test other ARVs to see if they might also work as PrEP
Immune system, HIV and vaccines • VIDEO
Vaccines • A vaccine is a substance that teaches the body to recognize and defend itself against bacteria and viruses that cause disease. • A vaccine causes a response from the immune system—the body's defense system—preparing it to fight, and also to remember how to fight, if exposed to a specific infection. • A vaccine is not a cure, but prevents infection or slows disease progression.
A vaccine primer • 200 years of vaccines • Common vaccines • Types of immunity: humoral (antibody) and cell-mediated • An ideal HIV vaccine • Preventative or therapeutic?
Challenges in HIV Vaccine Research • Designing the vaccine: need a different approach for HIV vaccines • Animal models: have not yet accurately predicted how they will work in humans • Unknown correlates of protection: don’t know what immune responses will protect an individual from infection • HIV mutation: there are many different subtypes of HIV, may require matching vaccines
…but on the bright side… • Broadly neutralizing antibodies found • Precedent from other systems: Success against other viral infections • Precedent from animal studies: Long-term control of infection in vaccinated monkeys • Immune control of HIV-1: Infected individuals control infection • Vaccine trials: In progress
Gender and HIV • What do we mean by “gender”? Is it the same as “sex”? • What factors influence vulnerability to HIV? • What impact does gender have on HIV prevention? • For women? • For men? For gay men?
What women need to protect themselves Social power Protection Economic opportunities Technology
Questions women have about ARV-based prevention If I think my husband has HIV, will I be able to get PrEP? If I use a microbicide, how will I make my man use a condom? Even if the doctor gives me pills, will I be able to keep them for myself?
More questions women have How much will it cost? Where will I get it? People will notice if I have to go in for testing and to get my pills. What will they say about me? Will it make me sick? Can I take PrEP when I am pregnant? Will it hurt my baby? What about breastfeeding? Will my husband let me go to the clinic?
