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Using Antiretroviral Therapy to Prevent HIV: Treatment as Prevention (TasP)

Discover the efficacy of ART as a prevention tool for HIV. Learn about TasP strategies, the history of TasP, and its acceptability and reservations. Explore the Test and Treat approach and its impact on HIV prevalence.

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Using Antiretroviral Therapy to Prevent HIV: Treatment as Prevention (TasP)

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  1. UsingAntiretroviralTHERAPYtopreventHIV

  2. Treatment as Prevention (TasP) • When adhered to consistently, ART can reduce your HIV viral load in the blood, semen, vaginal - and rectal fluid to such a low level that blood tests can’t detect it • This is described as an 'undetectable' viral load or viral suppression. In these circumstances, as long as your viral load remains undetectable , your health will not be affected by HIV and you cannot transmit HIV to others • Viral suppression can only be confirmed if you are accessing regular treatment support, monitoring and viral load testing from a healthcare professional THE EFFICACY OF ART AS A PREVENTION TOOL IS NOW UNDISPUTED!

  3. Five TasP strategies • Test & immediate treatment for all people living with HIV (PLWH) • Vaginal and rectal microbicides* • Pre-exposure prophylaxis (PrEP) • Post exposure prophylaxis (PEP) • Prevention of mother to child transmission (MTCT)

  4. History of TasP 2008 - The Swiss Statement • One of the first things we heard about the concept of TasP for sexual transmission was the Swiss statement • In summary the Swiss agreed…a person with HIV who was ‘taking antiretroviral therapy with completely suppressed viral activity is not sexually infectious, i.e. they cannot transmit HIV through sexual contact’ • There was no change in treatment policy initially but PLWH became increasingly aware of this issue

  5. July 2011 - A landmark study HPTN 052 • A multi-continent, randomised controlled trial set out to compare early ART versus delayed ART • Participants were PLWH, who were in a stable relationships, with CD4 counts of 350-500 • Randomised to either immediate ART or delayed ART until 2x consecutive CD4 counts were 250 cells/ml or less, or an illness related to AIDS

  6. HPTN 052 study results

  7. 2014 - The Partner study • A 4 year long study conducted across 14 European countries • > 1,000 ‘mixed-status’ couples enrolled • No HIV transmissions when the viral load of the positive partner was undetectable • Zero transmissions after couples had sex 58,000 times without a condom • Good evidence for the effectiveness of treatment as prevention in both gay and heterosexual couples

  8. May 2015 - START study • ‘Early therapy conveys a double benefit, not only improving the health of individuals but ... reducing the risk they will transmit HIV to others’[1] • This has ‘global implications for the treatment of HIV’[1] • ‘These results support treating everyone irrespective of CD4+ T-cell count’[2] [1] Anthony Fauci, Director US National Institute of Allergy and Infectious Disease (NIAID). NIH Press Release May 27th 2015 [2] Jens Lundgren, M.D., University of Copenhagen , co-chairs START study

  9. 2017 - Opposites Attract Study • Included 343 gay couples where one partner had HIV (with persistent viral suppression) & the other was HIV negative • Zero cases of transmission of the virus in 16,889 acts of condom-less anal sex

  10. EAGA / BHIVA guidance The risk of a person living with HIV, who is taking effective ART, passing HIV on to sexual partners through vaginal intercourse is extremely low, provided the following conditions are fulfilled: • There are no other sexually transmitted infections (STIs) in either partner • The person who is HIV positive has a sustained viral load below 50 HIV RNA copies/mL for more than 6 months and below 50 copies/mL on the most recent test • Viral load testing to support the use of ART as prevention should be undertaken regularly (i.e.3–4-monthly)

  11. Acceptability/ reservations • Concern regarding the importance of people being able to decide for themselves whether or not they take TasP • Concern about people seeing being virally undetectable as a “get out of jail free card”, meaning that it would make them feel they did not have to have safer sex • Respondents of NAM’s HIV Prevention Survey got terms confused and had very varied ideas about the efficacy of different prevention techniques NAM HIV Prevention Survey

  12. Test and Treat Strategies • The ‘Test and Treat’ approach, (i.e. anyone testing positive for HIV starts ART regardless of CD4 count), has contributed to a significant increase in the number of people on ART[1] • One study from South Africa estimated that universal voluntary HIV testing plus immediate treatment [for adults] would decrease HIV prevalence to 1% within 50 years[2] • A study in India in men who have sex with men (MSM) and intravenous drug users (IVDU) found a strong correlation between treatment, viral suppression and HIV incidence in large populations[3] • Universal ‘test and treat’ for of pregnant women reduces the risk of a mother transmitting HIV to her child by up to 95%[4] [1] UNAIDS (2016) ’Get on the Fast Track’; [2] Granich, M.D. et al (2009)The Lancet 373(9657):48-57; [3] Solomon, S.S et al (2016) The Lancet HIV 3(4): 183-190; [4] World Health Organization (WHO) ’Mother to child transmission of HIV’  [accessed Nov. 2017]

  13. Today - WHO guidelines Now call for ‘test and treat’ strategies: initiating all people diagnosed with HIV on to ART as soon as possible after diagnosis – as a way to decrease ‘community viral load’ and therefore reduce the rate of new HIV infections

  14. Still some challenges ahead • TasP is a key cornerstone of UNAIDS’ 90-90-90 targets- with the aim to end AIDS as a major public health threat by 2030 • As of July 2017, 20.9 million PLWH globally were accessing ART -up from 7.5 million in 2010 • However currently only 60% of people with HIV know their status • The remaining 40% (over 14 million people) still need to access HIV testing services  Global data from UNAIDS, ‘AIDS by the Numbers’, Nov. 2016

  15. And some questions & concerns • HIV drug resistance- concerns that the widespread use of ART at a population level could lead to a significant increase in levels of HIV drug resistance • So adherence (taking the treatments as prescribed) is critical • Might there be an impact on risk-taking sexual behaviours if you believe you or your partners are non-infectious? • How practical/accessible and cost effective is widespread up-scaling of testing and treatment? • Is there a danger of compulsory or coercive testing and treatment- i.e. might you feel pressurised into taking ART earlier? • Could this undermine the strong ,uncomplicated and still relevant messaging encouraging condom use?

  16. Microbicides • Microbicides are gels or creams containing antiretroviral drugs that are applied to the vagina or rectum to help prevent HIV infection • Vaginal microbicides are relatively effective, if used consistently and correctly • In 2016 The Ring and ASPIRE studies found that use of a monthly vaginal ring reduced rates of HIV acquisition by around one-third • The main challenge with microbicides is adherence • Studies into rectal microbicides, which are suitable for use during anal sex, are ongoing [1] https://www.ipmglobal.org/the-ring-study [2] https://www.avac.org/sites/default/files/u44/IPM-MTN-Sister-Studies.pdf

  17. Pre-exposure prophylaxis (PrEP) • A daily course of ART that can protect HIV-negative people from infection before exposure to the virus A daily course of ART that can protect HIV-negative people from infection before exposure to the virus • At present Truvada - i.e. a single pill combining two drugs (tenofovir and emtricitabine), is approved for use as PrEP • When PrEP is taken exactly as prescribed, it reduces the chances of HIV infection to near-zero[1] • PrEP should be offered as part of a combination package of prevention initiatives & based on individual circumstances[2] • PrEP is cost-effective for health care systems [1] IPERGAY and iPrEx studies [2] http://www.who.int/hiv/pub/arv/chapter3.pdf

  18. PrEP availability • Scotland - currently the only country in the UK that offers a full PrEP provision through their NHS • Wales - commenced the PrEPared Wales project • England - ’PrEP IMPACT’ commenced October 2017; enrolling 10,000 people • Northern Ireland - currently has no provision of PrEP https://www.iwantprepnow.co.uk/

  19. PrEP - Especially valuable for those who... • Are in a long term relationship with an HIV-positive partner • Have difficulty negotiating condom use • Are having repeated anal sex without a condom • Are sexually active in an area or community of high HIV prevalence • Share injecting equipment for IVDU but access to harm reduction education/needle exchange is emphasised • But for heterosexual individuals -biological efficacy is likely to be identical but there is currently a lack of supporting data http://www.bhiva.org/documents/Guidelines/PrEP/Consultation/PrEP-guidelines-consultation-2017.pdf

  20. PrEP – Pros and cons • Providing PrEP with annual HIV testing to just 25% MSM (with a high risk of HIV infection) could prevent over 7,000 new HIV infections by 2020[1] • But PrEP does not provide protection against other sexually transmitted infections and blood-borne illnesses[1] • MSM have the option to use the event based (on-demand) regimen evaluated in the IPERGAY trial or daily, unless they have active hepatitis B infection in which case a daily regimen is preferred to avoid hepatic flares when drug is interrupted and emergence of resistance • NHS England has only provided access to PrEP through small scale trials [1] Punyachaanroensin, N. et (2016),The Lancet HIV

  21. PrEP – Pros and cons (continued) • However generic PrEP is available to order via the internet • And is safe and effective – with no new cases of HIV seen among participants[1] • There is no evidence that PrEP leads to a reduction in condom use and other safer sex behaviour or STI rates[2] • However adherence is critical & challenging – rates vary considerably in studies[2] • Taking two doses a week – offers only about 70% protection (compared to over 90% if taken daily) • A number of factors adherence levels including knowledge and awareness of PrEP, its availability and the participants' lifestyle [1] Wang X et al (2017),HIV Med. [2] Cohen, S.E. et al (2014) 21st CROI, Abstract 954

  22. PrEP: Important considerations • PrEP only works if you take it! • Expect to be offered extensive HIV risk-reduction & adherence counselling • And HIV testing 2-3 monthly • It is important you are not in the ‘window period’ of HIV infection when beginning PrEP • Reliable use of condoms is still strongly advisable • Kidney function testing is recommended 3 months after starting PrEP and then annually • STI screening is also recommended every 6 months, even if you have no symptoms • Side effects are possible- stomach cramps, headaches and loss of appetite initially • Long-term use raises issues of kidney health and bone density

  23. PEP: Post-Exposure Prophylaxis • After sexual exposure, PEP usually involves taking a combination of 3 HIV drugs for one month • The earlier PEP is started, the more likely it could work (ideally, this should be within a couple of hours) • Must start taking it within 72 hours • HIV test at 1 month and 3 months after PEP treatment finishes • Available from sexual health clinics & A&E departments (via an HIV specialist). Note that GPs cannot prescribe PEP http://www.bhiva.org/documents/Guidelines/PrEP/Consultation/PrEP-guidelines-consultation-2017.pdf Image – THT.org.uk

  24. When is PEP recommended? • Receptive anal sex: with someone who is known to be HIV positive or who is thought to be from a high-prevalence country or risk group e.g. MSM • Insertive anal sex: with someone who is known to be HIV positive • Vaginal sex: with a man who is known to be HIV positive • Non-sterile injection equipment: if you have used injecting equipment previously used by someone who is known to be HIV positive • Post sexual assault: depending on the nature of the act • Health care workers: following certain exposures to blood/body fluids http://www.bhiva.org/documents/Guidelines/PrEP/Consultation/PrEP-guidelines-consultation-2017.pdf

  25. Preventing mother to child transmission • Programmes to prevent mother-to-child transmission were some of the earliest public health interventions that used ART to reduce the risk of HIV transmission • Initially a single dose of ART was given during labour (and then to the infant in the first few days of life) • Since 1999 in UK - all pregnant women are routinely offered an HIV test • In 2013, consolidated guidelines from WHO recommended that all pregnant and breastfeeding women be initiated on ART • Pregnant women should start ART before 24 weeks at the latest • For those already taking ART ,in most cases, the same medications can continue WHO-http://www.who.int/hiv/topics/mtct/about/en/ [accessed Jan 2018] www.bhiva.org/documents/Guidelines/Pregnancy/2012/BHIVA-Pregnancy-guidelines-update-2014.pdf [accessed Jan 2018]

  26. Preventing mother to child transmission • In the absence of any intervention, transmission rates range from 15% to 45%[1] • This is reduced to below 5% with effective interventions (including ART) during pregnancy, labour, delivery and breastfeeding[1] • In the UK, for those on effective ART with an undetectable viral load at delivery - risk of transmission is currently estimated to be < 0.6%[2] [1] WHO-http://www.who.int/hiv/topics/mtct/about/en/ [accessed Jan 2018] [2] www.bhiva.org/documents/Guidelines/Pregnancy/2012/BHIVA-Pregnancy-guidelines-update-2014.pdf [accessed Jan 2018]

  27. Any questions?

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