Is an HIV Vaccine in the Future?

Although people have more access to HIV medicine than ever before, the infection continues to spread, with over 1.3 million new HIV infections reported worldwide in 2022.  A vaccine could be the ultimate solution to end the HIV epidemic, and recent advancements in research are providing hope.

A vaccine is the ultimate solution to putting an end to the HIV epidemic. Thankfully, the ongoing research efforts and recent advancements in HIV vaccine development look promising. 

Existing Challenges

There is currently no approved vaccine for HIV. Creating an HIV vaccine has been difficult because HIV changes very quickly. The virus has an enzyme that makes many mistakes when it copies itself, leading to multiple versions of the virus in one person. 

Traditional vaccines work by prompting the body to produce antibodies against pathogens, but HIV can hide and change so well that these antibodies can't always recognize it. Because of this, traditional vaccines, like those for other diseases, aren't effective against HIV. New technologies like mRNA vaccines, which were used for COVID-19, also face challenges in producing enough of the right proteins to fight HIV.

To effectively combat HIV, a vaccine needs to trigger both antibodies and T-cells.

Antibodies are proteins made by the immune system to help fight infections. When a virus or bacteria enters the body, antibodies recognize and attach to it, marking it for destruction. Think of antibodies as the body's "search and tag" team. They find harmful invaders and tag them so other immune cells can destroy them. For HIV, special antibodies called broadly neutralizing antibodies (bNAbs) are needed because they can target many different types of the virus.

T-cells are a type of white blood cell that play a crucial role in the immune response.  

Ongoing Research and Promising Development

Developing an HIV vaccine has been a slow process. One trial showed a modest 31% reduction in HIV risk, but follow-up efforts haven't succeeded. Researchers think this is because previous vaccines relied on weak antibodies that couldn't effectively combat HIV.

However, there’s good news. A recent 2024 study published in Nature Immunology has made significant progress. Scientists have found a way to help the immune system produce strong antibodies that can fight many types of HIV. They tested this on animals and saw promising results, and similar results were observed using mRNA technology.

Several promising HIV vaccine candidates are currently in clinical trials. For example:

• VIR-1388: An NIH-funded vaccine developed since 2004, designed to produce T cells that can recognize and kill HIV-infected cells.
• HIV gp41 Vaccine: Researchers at Nature Immunology are working on a vaccine that stimulates the immune system to produce broadly neutralizing antibodies (bNAbs) to fight HIV.

These trials are essential for ensuring the safety and effectiveness of new HIV vaccines. They evaluate how well the vaccines trigger an immune response, protect against HIV, and identify any side effects.

Clinical trials are crucial for advancing HIV vaccine development. Participants have contributed valuable data that can lead to a potential vaccine. Reliable organizations like the National Institutes of Health (NIH) and IAVI support these trials and collaborate globally to accelerate progress.

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Sources:

1. UNAIDS | Global HIV & AIDS statistics
2. NEJM | Vaccination with ALVAC and AIDSVAX to Prevent HIV-1 Infection in Thailand
3. Nature | Vaccination induces broadly neutralizing antibody precursors to HIV gp41
4. Clinical Trials | To Investigate Safety, Reactogenicity and Immunogenicity of VIR-1388 Compared With Placebo in Participants Without HIV