May 18: HIV Vaccine Awareness Day

Edward Johnson, hi-tech and engineering expert, May 18, 2025

Where does HIV vaccine research stand?

As of 2026, there is still no effective vaccine against HIV. Scientists are focusing on antibodies called bNAbs, capable of recognizing multiple versions of the virus, even as it mutates. It's possible to activate the cells that produce these antibodies through a technique called "germline targeting." To do this, researchers use vaccines that contain genetic instructions in the form of mRNA, wrapped in lipid nanoparticles, meaning tiny droplets of fat. These particles protect the mRNA and help it enter the body's cells. Once inside, the cells read these instructions and produce a protein modeled on HIV. This protein acts as a warning signal: it allows the immune system to recognize the virus and begin producing defenses.

Different types of vaccines under study

Four types of HIV vaccines are currently being studied. The first type uses modified viruses, called vectors, which carry a piece of HIV to teach the body to defend itself. The second type directly contains purified pieces of the virus, which helps the body produce targeted antibodies, but requires several doses. The third type, using messenger RNA (mRNA), gives the body instructions to make part of the virus itself, which triggers a fast and precise immune response. Finally, the fourth type of vaccine uses plasmid DNA, meaning small fragments of lab-designed DNA, which contain the instructions to produce an HIV protein. Once injected, this DNA enters cells and prompts them to make this protein, triggering an immune response.

Scientific obstacles

The HIV virus produces thousands of new versions of itself every day within a single body. In addition, this protein is covered with a coat of sugars that hides sensitive areas, preventing antibodies from properly recognizing it. Finally, the virus settles very quickly into certain cells in the body, hiding within their DNA, which makes it inaccessible.