HIV (human immunodeficiency virus) is a virus that weakens the immune system and hinders the body’s ability to fight disease. Without treatment, HIV could lead to the potentially fatal diagnosis of AIDS (acquired immune deficiency syndrome).

The AIDS epidemic began in the United States in the 1980s. The World Health Organization (WHO) estimates that HIV has claimed over 35 million lives since it was first discovered.

There’s currently no cure for HIV. However, there are many clinical studies dedicated to researching a cure for HIV. The current antiretroviral treatments allow people living with HIV to prevent its progression and to live normal lifespans. Scientists, public health officials, governmental agencies, community based organizations, HIV activists, and pharmaceutical companies have made great strides toward preventing and treating HIV.

The development of a vaccine for HIV would save millions of lives. However, researchers haven’t yet discovered an effective vaccine for HIV.

In 2009, a study published in the Journal of Virology found that an experimental vaccine prevented about 31 percent of new infections. However, further research was stopped due to dangerous risks.

In early 2013, the stopped a clinical trial that was testing injections of the HVTN 505 vaccine. Data from the trial indicated the vaccine didn’t prevent HIV infection or reduce the amount of HIV in the blood.

Research into vaccines is ongoing throughout the world. Every year there are new discoveries and clinical trials.

While no vaccine is yet available for HIV, there are ways to protect against transmission.

HIV is transmitted through the exchange of bodily fluids. This can happen in a variety of ways, including:

  • Sexual contact. HIV can be transmitted through the exchange of certain fluids during sexual contact, including blood, semen, or anal and vaginal secretions. Having other sexually transmitted infections (STIs) can increase the risk of HIV transmission during sex.
  • Shared needles and syringes. Needles and syringes that have been used by a person with HIV may contain HIV even without visible blood.
  • Pregnancy, delivery, and breastfeeding. Mothers with HIV can transmit the virus to their baby before and after birth, though this is extremely rare with the use of HIV medication.

Taking precautions may protect you from contracting HIV. Here are a few tips for protecting yourself:

  • Get tested for HIV and know your partner’s status before you have sex.
  • Get tested and treated for STIs.
  • Use condoms correctly every time you have oral, vaginal, and anal sex.
  • If you inject drugs, make sure to use a new, sterilized needle that hasn’t been used by anyone else.

Pre-exposure prophylaxis (PrEP) is a daily medication used by someone without HIV to lower their chances of contracting HIV, if exposed. It’s highly effective in preventing the transmission of HIV in high-risk populations. Populations at risk include:

  • men who have sex with men, if they’ve had anal sex without using a condom or had an STI in the last six months
  • men or women who don’t use condoms regularly with partners at high risk of HIV infection and of unknown HIV status
  • anyone who has injected drugs in the last six months or shared needles
  • women who are considering getting pregnant with HIV-positive partners

According to the , PrEP can reduce the risk of HIV infection by up to 92 percent in populations who are at high risk if taken consistently. Choosing PrEP as a prevention method requires adherence to the daily schedule.

Post-exposure prophylaxis (PEP) is emergency antiretroviral drugs used after someone may have been exposed to HIV. Healthcare providers may recommend PEP in the following situations:

  • A person thinks they may have been exposed to HIV during sex (the condom broke or no condom was used).
  • A person has shared needles when injecting drugs.
  • A person has been sexually assaulted.

PEP should be used only as an emergency prevention method. It must be started within 72 hours of exposure, though ideally it should be started as close to the time of exposure as possible. A healthcare provider will prescribe multiple drugs for this prevention method and typically involves a month of adherence to antiretroviral therapy.

Diagnosing HIV and AIDS is a vital step toward preventing the transmission of the virus. WHO estimates that 40 percent of the 18 million people with HIV don’t know they have the disease.

There are several different blood tests healthcare providers can use to screen for HIV. HIV self-tests allow people to test their saliva or blood in a private setting and receive a result within 20 minutes or less.

Thanks to advances in science, HIV is considered a manageable chronic disease. Antiretroviral treatment allows people living with HIV to maintain their health. It also reduces their risk of transmitting the virus to others.

WHO estimates that more than 80 percent of all people diagnosed with HIV receive some type of antiretroviral therapy.

The medications used to treat HIV do two things:

  • Reduce viral load. The viral load is a measure of the amount of HIV RNA in the blood. The goal of HIV medication therapy is to reduce the virus to an undetectable level.
  • Allow the body to restore its CD4 cell count to normal. CD4 cells are responsible for protecting the body against pathogens that can cause infection.

There are several types of HIV drugs:

  • Non-nucleoside reverse transcriptase inhibitors disable a protein that HIV uses to make copies of its genetic material in the cells.
  • Nucleoside reverse transcriptase inhibitors give HIV faulty building blocks so it can’t make copies of its genetic material in the cells.
  • Protease inhibitors disable an enzyme HIV needs to make functional copies of itself.
  • Entry or fusion inhibitors prevent HIV from entering your CD4 cells.
  • Integrase inhibitors prevent integrase activity. Without this protein, HIV can’t insert itself into the CD4 cell’s DNA.

HIV drugs are often taken in specific combinations to prevent the development of drug resistance. HIV drugs must be taken consistently to be effective. The decision to switch medications to reduce side effects of the medication or because of treatment failure is a conversation that healthcare providers and people living with HIV take seriously.

Research has shown that achieving and maintaining an undetectable viral load through antiretroviral therapy effectively eliminates the risk of transmitting HIV to a sexual partner.

have found no instances of HIV transmission from a persistently virally suppressed (undetectable viral load) HIV-positive partner to an HIV-negative partner. These studies followed thousands of couples with different HIV statuses over several years and thousands of instances of sex without condoms.

With awareness that U=U (“undetectable = untransmittable”) comes greater emphasis on “treatment as prevention.” UNAIDS has a “90-90-90” goal to end the AIDS epidemic. By 2020, this plan aims for:

  • 90 percent of all people living with HIV to know their status
  • 90 percent of all people diagnosed with HIV to be on antiretroviral medication
  • 90 percent of all people receiving antiretroviral therapy to be virally suppressed

Researchers are hard at work looking for new drugs and treatments for HIV. They’re aiming to find therapies that extend and improve the quality of life for people with this condition. In addition, they hope to develop a vaccine and discover a cure for HIV. Here’s a brief look at several important avenues of research.

Targeting HIV reservoirs

Part of what makes discovering a cure for HIV difficult is that the immune system has trouble targeting reservoirs of cells with HIV. The immune system usually can’t recognize cells with HIV nor can it eliminate the cells that are actively reproducing the virus.

Antiretroviral therapy doesn’t eliminate HIV reservoirs. So are exploring two categories in the search for an HIV cure:

  • Functional cure. This type of cure would control replication of HIV.
  • Sterilizing cure. This type of cure would completely eliminate the part of the virus responsible for replicating.

These cures would potentially destroy HIV reservoirs.

Breaking apart the HIV virus

Researchers at the University of Illinois at Urbana-Champaign have been using computer simulations to study the HIV capsid, the container for the virus’s genetic material. This capsid protects the virus from being destroyed by the immune system.

Understanding the makeup of the capsid and how it interacts with its environment may help researchers find a way to break the capsid open, releasing the genetic material of HIV into the body where it can be destroyed by the immune system. It’s a promising frontier in HIV treatment and cure.

‘Functionally cured’

A man in Berlin living with HIV also had leukemia. He received a stem cell transplant to treat the leukemia. HIV hasn’t been detected in “the Berlin patient” for over 10 years since that procedure.

Studies of multiple parts of his body at the University of California, San Francisco have shown him to be free of HIV. He’s considered “effectively cured,” according to the . However, this success hasn’t been repeated since.

In early 2013, the announced that a 2-year-old child in Mississippi who was born to an HIV-positive mother had been “functionally cured” of HIV. Doctors administered antiretroviral treatment during the infant’s first day. The baby remained on the antiretroviral therapy for the first 18 months of life, and doctors performed regular blood tests to check the levels of HIV.

The baby was still HIV-free as far as tests could detect 10 months after stopping medication. Many researchers considered the child to be “functionally cured.” However, two years after ending antiretroviral therapy, were found in the child’s blood. The child was no longer considered cured, and resumed antiretroviral treatment.

Researchers barely understood HIV 30 years ago, let alone how to treat or cure it. Over the decades, advances in technology and medical capabilities have brought more advanced HIV treatments. Each year, hundreds of clinical trials aim to find better treatments for HIV in the hopes of one day finding a cure. With those new treatments come better methods of preventing the transmission of HIV.

Successful antiretroviral treatments can now halt the progression of HIV and can decrease a person’s viral load to undetectable levels. Having an undetectable viral load not only promotes a person’s own continued health, it eliminates the risk of transmitting the virus to a sexual partner. Targeted drug therapy can also prevent pregnant women with HIV from transmitting the virus to their children.