Biomedical Prevention – The Future of HIV Prevention!

Traditionally, HIV prevention methods have included the use of condoms, clean needles, and behavior change. While those methods are effective, scientists are looking for medical strategies to prevent the spread of HIV. Experts believe that there will not be a “one size fits all” prevention strategy and the National Institutes of Health has created a prevention “toolbox” that includes both traditional and newer prevention methods. Communities across the U.S. can pick and choose from this tool box and use the prevention method(s) that work best for them.

Below are five biomedical prevention strategies from the toolbox that are currently being used. The short description provides basic information about each, followed by links for additional information.

Pre-Exposure Prophylaxis (PrEP)

Post-Exposure Prophylaxis (PEP)

Vaccines

Microbicides

Treatment as Prevention

PRE-EXPOSURE PROPHYLAXIS (PrEP)

Since prophylaxis means disease prevention, Pre-Exposure Prophylaxis, or PrEP, is a strategy that involves use of antiretroviral medications (ARVs) in HIV-negative individuals before they become exposed to the virus to reduce the risk of HIV infection via sexual exposure or injection drug use. Currently, the anti-HIV drug known as Truvada has been approved by the FDA for use as PrEP. This is the first ARV to be approved for HIV prevention in HIV-negative adults.

For more information about PrEP, how to get it, its cost, and whether you or someone you know is a good candidate, please visit the APLA Health & Wellness website’s section on the Pendleton / Goldman PrEP Program at www.aplahw.org/prep.

POST-EXPOSURE PROPHYLAXIS (PEP)

Since prophylaxis means disease prevention, Post-Exposure Prophylaxis, or PEP, is a strategy that involves taking anti-HIV drugs as soon as possible after you may have been exposed to HIV to try to reduce the chance of becoming HIV-positive. To be effective, PEP must begin within 72 hours of exposure, before the virus has time to rapidly replicate in your body. Several HIV medications are indicated for use in PEP and are taken for a period of 28 days to prevent a new HIV infection.

What are the different types of Post-Exposure Prophylaxis?
PEP involves taking anti-HIV drugs as soon as possible after you may have been exposed to HIV to try to reduce the chance of becoming HIV-positive. There are two types of PEP: (1) occupational PEP, (sometimes called "oPEP"), and (2) non-occupational PEP, (sometimes called “nPEP”). Workplace exposure (oPEP) is when someone working in a health-care setting is potentially exposed to material infected with HIV. nPEP is when someone is potentially exposed to HIV outside the workplace (e.g., condom breakage, sexual assault, etc.)

To be effective, PEP must begin within 72 hours of exposure, before the virus has time to rapidly replicate in your body. PEP consists of 2-3 antiretroviral medications and should be taken for 28 days. Your doctor will determine what treatment is right for you based on how you were exposed to HIV. The medications have serious side effects that can make it difficult to finish the program. PEP is not 100% effective; it does not guarantee that someone exposed to HIV will not become infected with HIV.

Who needs PEP?
PEP is usually used for anyone who may have been exposed to HIV. Health care workers have the greatest risk. They can be exposed to HIV by:

  • Needle sticks or cuts
  • Getting blood or other body fluids in their eyes or mouth
  • Getting blood or other body fluids on their skin when it is chapped, scraped, or affected by dermatitis.

The risk of HIV transmission in these ways is extremely low—less than 1% for all exposures. PEP can also be used to treat people who may have been exposed to HIV by accident (e.g., condom breakage) or sexual assault.

When should I take PEP if I’ve been exposed?
PEP is most effective if you take it within 72 hours of possible HIV exposure. The longer you wait to start PEP, the greater the risk of becoming HIV-positive.

Your healthcare provider will consider whether PEP is right for you based on how you might have been exposed and whether you know for sure that the individual who might have exposed you is HIV-positive. You may be asked to return for more HIV testing at four to six weeks, three months, and six months to determine your HIV status.

Where can I get PEP?
Some of the places you can go to seek treatment include your doctor’s office, emergency rooms, urgent care clinics, or a local HIV clinic. In Los Angeles County, The County of Los Angeles, Department of Public Health funds two clinics to provide PEP free of charge to those people at risk for HIV infection who do not have insurance to pay for the medication. Testing and counseling are also provided at these clinics. The clinic sites are The Los Angeles LGBT Center (Hollywood area): 1625 N. Schrader Blvd., Los Angeles, CA 90028, phone: 323.860.5880; and the OASIS Clinic (near Downtown/Compton): 1807 E. 120th St., Los Angeles, CA 90059, phone: 310.668.5131.

VACCINES

A vaccine improves immunity to a particular disease. Vaccines are designed to stimulate the body's own immune system to recognize a virus or bacteria as an invader, destroy it, and "remember" it so that the immune system can more easily recognize and destroy any of these invaders that it later encounters. In other words, vaccines trick your immune system to teach your body important lessons about how to defeat the invaders. Researchers have been working on a preventative vaccine for some time. There have been several breakthroughs in the last few years, but they have not yet developed a vaccine that works for at least 80% of the study participants who have received the vaccine. This is one reason why vaccine research is so important. HIV vaccines DO NOT contain live virus and a person cannot get HIV from an HIV vaccine.

What is an AIDS vaccine?
An AIDS vaccine is an experimental strategy that aims to teach the body's immune system how to fight HIV to reduce the risk of infection or to reduce viral load in those who get the vaccine and go on to become infected. All of the candidates being studied are experimental; there are no effective AIDS vaccines available today. None of the vaccines being tested can cause HIV.

Why are we looking at AIDS vaccines?
Vaccines are one of the world's most effective public health tools. Effective vaccines against polio, measles, mumps, rubella and other diseases have significantly reduced rates of these illnesses in many parts of the world. Today, many scientists, clinical trial teams and communities are working together on the search for an AIDS vaccine.

AIDS vaccine scientists are developing candidates that aim to block HIV infection in HIV-negative people, as well as candidates that aim to reduce viral load in people who receive the vaccine while HIV-negative and go on to become infected. Viral load is linked to disease progression, so a vaccine that reduced viral load could result in improved health and delayed time to initiation of antiretroviral treatment. Scientists are also developing therapeutic vaccines which would build immune strength in HIV-positive people.

What is in the pipeline for AIDS vaccines of the future?
There are a range of candidates in early stages of development, and a wide range of basic scientific work (work not focused on product development) ongoing in the AIDS vaccine field.

MICROBICIDES

Microbicides are being studied in research in people at risk for HIV infection. The hope is that microbicides will be easy to use, when condoms are not always a reality, and will kill all HIV before it can infect the person who uses them. Microbicides are currently being studied in different forms: foam, gel, cream or slow-release vaginal ring, all of which contain an anti-HIV drug. The foam, gel, cream, ring or suppository gets inserted into the vagina and/or rectum to reduce the risk of HIV transmission during sex. Advances have been made in both vaginal and anal microbicides, but none have been approved by the Food & Drug Administration.

The idea for a microbicide-like product was first proposed more than 20 years ago by reproductive health specialists and advocates who recognized the need for female-controlled HIV prevention methods. One of the first products considered was the spermicide nonoxynol-9 because researchers believed it might also be effective against HIV. Unfortunately, research showed it was neither safe nor effective against HIV. Other trials of different so-called first generation microbicides also proved unsuccessful. These included products intended to strengthen natural defenses in the vagina or create a barrier to protect target cells in the vagina.

What will it take to discover a safe and effective microbicide?
Testing many products is necessary before finding even one microbicide that will be safe and effective against HIV and also easy and acceptable to use. Different products work in different ways, and researchers do not yet know which ones will work best. A handful of candidate microbicides are in various stages of clinical study; additional compounds are in early stages of development.

TREATMENT AS PREVENTION

Treatment as prevention is an effective prevention strategy because the HIV medications today are potent and durable enough to lower HIV viral loads to undetectable levels in the blood and keep it there. That is why it is important to take the HIV medication as prescribed. Treatment as prevention works as a dual-strategy since we know that treatment leads to undetectable virus in a person living with HIV. By taking the HIV treatment as prescribed, this shuts down production of HIV and allows the immune system to rebuild itself and make healthy new T-cells. This improves the health of the person living with HIV. Also, we know from studies that people who maintain undetectable HIV viral loads are much less likely to transmit the virus during sexual encounters. This helps to decrease the number of new HIV infections. The more people living with HIV on effective treatment, the less HIV that is out there in the community.

MORE INFORMATION

Where can I get more information about HIV Biomedical Research?
The following websites are excellent resources:

APLA’s Policy Brief on TasP, PrEP, and PEP
The International HIV Vaccine Advocacy Initiative
PrEP Facts
CDC on PrEP
CDC on PEP
The AIDS Vaccine Advocacy Coalition
AIDS Research Alliance
UCLA CARE Center

If you have any questions regarding the content of this page or would like to know more about biomedical prevention, please visit the links in the fact sheets or contact APLA’s Treatment Education Program at 213.201.1616.