HIV Pre-Exposure Prophylaxis (PrEP) Online Course at Coursera Review. Day 14 of 42.
On the 14th day, participants of the PrEParing course on Coursera online education platform are offered to pass a quiz.
The commitment is not to disclose the questions and solutions of the test tasks. So we designed own questions suggesting you recall the methods of preventing HIV — PEP, and PrEP. Answers to the questions will be posted in a week, on the 21st day of the course. Also, we share the answers to the problems of the first week.
— is the use of antiretroviral drugs by people without HIV, to prevent the transmission of HIV in future if in their life there are situations of substantial risk of exposure to HIV. It is another option for HIV prevention in addition to using condoms and lubricants, counseling aimed at behavior change, post-exposure prophylaxis, treatment of sexually transmitted infections, voluntary male circumcision and antiretroviral therapy for partners living with HIV. The most commonly used form of PrEP is a combination of tenofovir (TDF, 300 mg) and emtricitabine (FTC, 200 mg) in the form of a pill for taking it once a day.
«Oral pre-exposure prophylaxis. Putting a new choice in context», UNAIDS, 2015, edited by Life4me+.
The risk of getting HIV fluctuates widely, depending on the type of exposure or behavior (e.g., needle exchange or syringes, sexual contact without a condom). Some impacts carry a much higher risk of transmission. For some impacts, while the transmission is biologically possible, the risk is so small that it is impossible to measure. But the risks develop over time. Even relatively small risks can develop over time and lead to a high risk of HIV transmission. In other words, there may be a little probability of acquiring HIV when a person engages in risky behavior with an infected partner only once. But if such a person repeat this risky behavior (impact) many times, the overall probability of HIV transmission after repeated exposures increases many times.
Transmission of HIV can occur when blood, semen, vaginal secretions from a person with HIV are found, in which the virus is not suppressed by antiretroviral therapy, into the blood or mucous membranes of a person without HIV. It is possible to transmit HIV to the newborn from the mother during pregnancy (intrauterine), during labor or breastfeeding, in cases where the mother does not receive antiretroviral drugs. There are no other routes of HIV transmission registered.
An undetectable viral load is a condition in an HIV-positive person, in which the number of virus particles in the blood is below the threshold required for detection by a laboratory test. The results of measuring the amount of virus in the blood (viral load) are indicated in the number of copies of virus particles in one milliliter of blood (copies/ml). If a person is on antiretroviral therapy, his/her viral load should drop below the threshold level — less than 50 copies/ml or less than 20 copies/ml, depending on the model and the resolution of the laboratory equipment. Reaching an undetectable viral load is a key goal of Antiretroviral Therapy (ART). There is now evidence-based confirmation that the risk of HIV transmission from a person living with HIV, who is on Antiretroviral Therapy (ART) and has achieved an undetectable viral load in their blood for at least 6 months is negligible to non-existent.
If a person has HIV and undetectable viral load in the blood — what are the risks of an HIV-negative person getting HIV in case of one-time unprotected sex with him or her?
There is now evidence-based confirmation that the risk of HIV transmission from a person living with HIV, who is on Antiretroviral Therapy (ART) and has achieved an undetectable viral load in their blood for at least 6 months is negligible to non-existent. However, one should not forget about sexually transmitted bacterial infections (STIs) possibly transmitted during sexual intercourse — syphilis, gonorrhea, chlamydia. In cases of hard sex, it is worth remembering the risk of transmission of viral Hepatitis B and C. It is necessary to use a condom in all cases of sexual contact with a person you don’t know. If such risky behavior happens in your life often, consider starting PrEP and use it together with a condom.
As for May 2017, the only drug approved for use for PrEP is Truvada by Gilead Sciences, a tablet that consists of a combination of tenofovir and emtricitabine (TDF/FTC) antiretroviral drugs. Truvada was approved by FDA for PrEP in 2012. Such a pill should be taken once a day without interruptions. The drug reaches the required concentrations in human tissues 21 days after starting taking the drug.
In the coming years, new forms of PrEP are expected to appear like implantable devices, gels, rings, injections and solutions for infusions, self-dissolving tablets.
Tenofovir and emtricitabine, parts of the Truvada pills only approved for PrEP as for May 2017, blocks HIV enzyme ’reverse RNA-transcriptase’ and inhibit virus particles replication. As a result of such inhibition, the growth in the number of viral particles in the body stops and the infection does not develop. PrEP can be compared with birth control pills, which are taken every day.
Until 2012, PrEP was just an experiment; many researchers were skeptical about this practice. The situation changed in 2012 when the US Food and Drug Administration (FDA) approved the Truvada drug for pre-exposure prophylaxis of HIV infection. A large international clinical trial among gay and transgender women, iPrEx OLE, showed that PrEP reduces the risk of HIV transmission by at least 92% if taken consistently. PrEP is also effective when used by heterosexual men and women, as well as people who use injecting drugs.
Possibly yes, but not recommended continuing PrEP and practicing sexual intercouses with HIV-positive partner during pregnancy.
“In the PrEP trials with heterosexual women, medication was promptly discontinued for those who became pregnant, so the safety for exposed fetuses could not be adequately assessed. A single small study of the periconceptional use of tenofovir (TDF) in 46 uninfected women in HIV-discordant couples found no ill effects on the pregnancy and no HIV infections. Additionally, because tenofovir (TDF) and emtricitabine (FTC) are widely used for the treatment of HIV infection and continued during pregnancies that occur. The data on pregnancy outcomes in the US Antiretroviral Pregnancy Registry provide no evidence of adverse effects among fetuses exposed to these medications.
Providers should educate HIV-discordant couples who wish to become pregnant about the potential risks and benefits of all available alternatives for safer conception and if indicated make referrals for assisted reproduction therapies. Whether or not PrEP is elected, the HIV-positive partner should be prescribed adequate antiretroviral therapy before conception attempts: if the infected partner is male, to reduce the risk of the transmission-related viral load in semen; and in both sexes, for the benefit of their health.
The safety of PrEP with TDF/FTC or TDF alone for infants exposed during lactation has not been adequately studied. However, data from studies of babies born to HIV-infected mothers and exposed to TDF or FTC through breast milk suggest limited drug exposure. Additionally, the World Health Organization has recommended the use of TDF/FTC or 3TC/efavirenz for all pregnant and breastfeeding women for the prevention of perinatal and postpartum mother-to-child transmission of HIV. Therefore, providers should discuss current evidence about the potential risks and benefits of beginning or continue PrEP during breastfeeding so that an informed decision can be made.”
“Preexposure prophylaxis for the prevention of HIV infection in the United States — 2014. A clinical practice guideline,” US Public Health Service, p. 41.
The risk of HIV transmission increases during pregnancy, as well as the risk of HIV transmission to a child born to a mother who is transmitted HIV during pregnancy or breastfeeding. Therefore, for an HIV-negative woman whose sexual partner or is HIV-positive, PrEP can be beneficial if a doctor monitors the condition of the woman and the fetus.
However, in the past question, it was noted that the potential risks for the fetus and the newborn from taking PrEP by the mother were not fully understood. There are no data on serious contraindications for children and adults, but there is also no proven data on the absence of contraindications.
Possible tactics for planning a child in a family where the woman is HIV-negative and the male partner is HIV-positive is achieving by the male partner the undetectable viral load. A possible way for a woman to get pregnant is a natural way with the discontinuation of PrEP by a woman immediately after the fact of pregnancy, or using assisted reproductive technologies, such as in-vitro fertilization with washed sperm of the male HIV-positive partner.
PrEP is a variant of highly active antiretroviral therapy (ART). The principle of this therapy is to create a concentration of the drug in the body tissues that can suppress the virus particles replication in cells and prevent the spread of HIV in the body.
Therefore, if you were prescribed PrEP in the form of tablets for daily intake — you should take these pills every day, at the same time. In case if you forgot to take a pill — you need to take it as soon as possible and continue intake in the next day without interruptions.
Once every three months, you need to show your doctor for check up.
As for May 2017, the only approved medication for PrEP, Truvada, creates a protective barrier in the tissues of the rectal mucosal tissues 7 days after putting on PrEP.
As for May 2017, the only approved medication for PrEP, Truvada, creates a protective barrier in the tissues of the vaginal mucosal tissues 21 days after putting on PrEP.
One package of Truvada with 30 tablets, sufficient for one month of PrEP, costs in Europe about 800 euros plus the added expenses of office visits and lab work. Other sources report the cost of 13 thousand dollars (about 9,500 euros) per year, so only a small number of people can afford the purchase of this drug on their own.
The high cost of officially approved antiretroviral drugs for PrEP leads to the emergence of illegal generics on the market. For example, the cost of Indian equivalents Truvada is only about 60 euros.However, the use of illegal medicines is fraught with the danger of a lack of permanent medical control, which is necessary when using PrEP drugs.
In June 2017, the US Food and Drug Administration (FDA) approved Teva Pharmaceuticals’ Truvada generic, and this could reduce the price of PrEP but earlier that 2021 when Gilead’s patents for emtricitabine, the second component of the drug Truvada, will expire.
Many countries start providing PrEP for free to people at risk. Despite the UNAIDS recommendation to provide PrEP to people at high risk of exposure to HIV free in all countries, its accessibility in the world remains limited. In Eastern Europe and Central Asia (EECA), PrEP is not yet available, although, in Georgia, Ukraine, and Azerbaijan, demonstration projects of PrEP are being started. The Ministry of Health of Kyrgyzstan plans to begin assessing the feasibility of implementing the PrEP in the country.
PrepWatch website offers current statuses of PrEP in all countries.
The high-risk group includes:
- Gays, bisexuals and other men who have sex with men;
- Sex workers and sex workers of all gender identities;
- Transgender women who have sex with men and who are the most disproportionately burdened of any population worldwide;
- Women and girls in the southern and eastern African hyper-epidemic setting;
- Uninfected sexual partners of people living with HIV across all kinds of relationships, heterosexual, same sex, male, and trans;
- Adolescents from all the communities mentioned above, namely teenage boys who practice same-sex;
- Adolescent sex workers all genders and gender identities;
- Adolescents who inject drugs;
- Transgender adolescent women.
If you cover by PrEP all people at risk — what changes could be expected? What will happen to the rate of HIV spread in such a community?
This task, probably, should be solved with the use of mathematical modeling. However, you could make preliminary assessments. So, in London in 2016, the number of new HIV cases dropped by 40% compared to 2015. Researchers explain this to the appearance in the city of a major clinic of sexual health, offering PrEP to people at risk.
Like condoms, PrEP works if you use it. If you take PrEP drugs every day, consistently and correctly, PrEP will reduce the risk of getting HIV by 90-95%, regardless of whether you use a condom or not. PrEP does not protect against STDs — gonorrhea, chlamydia or syphilis, and will not prevent pregnancy, while condoms protect against HIV, STIs, and pregnancy.
Condoms have been and remain an effective tool for reducing the risk of HIV, but many people do not use condoms every time they have sex. PrEP is an additional tool for HIV prevention. PrEP will work for your protection when you decide not to use a condom.
Therefore, it is up to you to decide this question. One of the options is to use PrEP and condom during contacts with strangers, switch to PrEP without a condom if you enter into a permanent monogamous relationship with an HIV-positive partner and discontinue PrEP if you enter into a stable monogamous relationship with an HIV-negative partner.
Yes, PrEP and a condom can be used together. Then the condom will protect against HIV, bacterial infections such as syphilis, gonorrhea, and chlamydia. PrEP will create a second outline of your safety, protecting you from HIV if the condom breaks or you choose not to use a condom.
It is worth remembering that if a condom is not used, there is a risk of getting bacterial infections, such as syphilis, gonorrhea, and chlamydia.
Can an HIV-negative person live with an HIV-positive person and regularly engage in unprotected sex without a condom without the risk of HIV transmission? When is this possible?
Yes, an HIV-negative person can live with an HIV-positive person and regularly engage in unprotected sex without a condom with no risk of HIV transmission. It’s possible if the HIV-positive partner is taking antiretroviral therapy he/she is undetectable for more than six months (undetectable viral load). It is believed that HIV-positive people with undetectable viral load can not transmit HIV to someone else.
For additional protection, the HIV-negative partner may start taking PrEP after consulting with a doctor. Then the HIV-negative partner will be protected from HIV in those rare cases when the viral load in the blood and biological fluids of the HIV-positive partner rises. This could happen if the antiretroviral drugs of an HIV-positive partner will stop working because of the drug resistance that develops, or if a person stops taking the drugs on a regular basis.
- What is post-exposure HIV prophylaxis?
- The woman had sexual intercourse with a guy without a condom. The next day she found out that he had HIV. What should she do?
- What are new forms of drugs for PrEP being developed in the world?
- How much should I wait after starting the course of PrEP to engage in anal sex?
- How much should I wait after starting the course of PrEP to engage in vaginal sex?
- How long does it take to wait after installing the vaginal ring with PrEP for safe sex?
- Is PrEP safe for the body?
- In which case, a person will be offered to switch to PrEP after a course of nPEP finished?
Try to answer these questions yourself. We will publish our opinion on these questions on the 21 day of this review, so stay tuned!
Tomorrow we are waiting for the first day of the third module. If you have not already signed up for the PrEParing course on the Coursera platform, it’s never too late to do it, just go to https://www.coursera.org/learn/prep.
Stay with us and stay healthy!