How close are we to a HIV vaccine?

A big step forward... but we are not there yet!

More than 40 years after HIV (human immunodeficiency virus) was first identified, scientists are finally getting closer to something we've long hoped for..... a vaccine to prevent it. HIV has proven to be one of the toughest viruses to crack, but recent progress is bringing new hope.

Why does a HIV vaccine matter?

HIV still affects millions of people around the world, especially in parts of Africa and LMICs (low-middle income countries). Advances have been made over the year, and antiretroviral therapy (ART) can help people manage their condition and live long, healthy lives, however, to date, there is no cure for the virus and many people (particularly in LMICs) still do not have reliable access to these treatments.

A HIV vaccine would be a real revolution in the field and could:

• prevent infection from happening in the first place

• protect people who are most at risk

• put us on a path to ending the global HIV epidemic.

A promising new approach?

In 2025, researchers made a major breakthrough using a vaccine based on mRNA technology. This is the same technology that was used in the COVID-19 vaccines. What makes this approach special is its clever design, as it teaches the immune system how to build the specific kind of response needed to fight HIV.

How it works:

1. The first injection (the “prime”) delivers instructions that activate rare immune cells called “germline B cells.” These cells are the ones capable of eventually producing the powerful HIV-blocking antibodies scientists have been chasing for decades.

2. The second injection (the “boost”) nudges those cells to develop further—to start producing what are called broadly neutralizing antibodies (bnAbs). These are special because they can block many different strains of HIV, not just one.

This approach is called “germline targeting,” and while it’s been tested in animals before, the 2025 results marked the first time it worked successfully in humans.

Two early-stage trials were conducted in the US and Africa (including Rwanda and South Africa), and across both trials it was found:

• Nearly all participants (97–100%) responded to the priming shot by activating the right type of B cells.

• Over 80% of those who received both shots developed what scientists call “elite” immune responses. This means their immune systems showed strong signs of being able to eventually produce bnAbs*.

• Importantly, these responses were seen across different populations, including those in sub-Saharan Africa, where the need for a vaccine is most urgent.

This was a huge moment. It showed we can begin steering the immune system in the right direction toward an effective HIV vaccine.

*bnAbs are broadly neutralising antibodies - they are a special type of antibody that can recognise and block many different strains of HIV, even though the virus mutates rapidly and has many variations.

What else is in the pipeline?

Researchers aren’t relying on just one idea. A separate 2025 trial in sub-Saharan Africa tested a different vaccine approach focused on triggering strong T-cell responses (another key part of the immune system). The results were also encouraging, with 99% of people developing robust responses, showing that even if one vaccine doesn’t work, others might.

In addition, recent animal studies showed that other stepwise vaccination strategies could help monkeys develop the exact kinds of antibodies we want to see in humans. These results are feeding directly into the design of future human trials.

What challenges still remain?

Progress is never smooth, and challenges still remain to pave the road ahead:

• Side effects were recorded - some people in the mRNA vaccine trial developed mild but persistent skin reactions. Researchers are studying these side effects to understand how serious they are and how to prevent them.

• There have been failures - previous large-scale HIV vaccine trials (like HVTN 702) failed to offer protection, which makes funders and policymakers cautious.

• Funding has been a real concern - in 2025, several funders scaled back support for HIV vaccine development, which could delay trials and slow down progress unless new resources are committed.

How close are we really?

We are closer than ever before, but we are not there yet.

The fact that we now have a vaccine that can start the process of making HIV-blocking antibodies in humans is a huge breakthrough. However, we still need larger trials to see if these vaccines actually prevent HIV infection, and researchers will need to keep tweaking the formulas to improve and expand. immune responses and safety.

Is real hope is on the horizon?

A vaccine won’t replace current treatments, but it could finally give us a tool to stop HIV before it spreads. After decades of setbacks, we are finally seeing progress that feels like the real thing.

With continued support, smart science, and global cooperation, we may be closer than ever to a world where no one has to worry about HIV.

References

• IAVI / Scripps Research. (2025). Two HIV vaccine trials show proof of concept for pathway to broadly neutralizing antibodies.

• Science. (2025). Germline-targeting HIV vaccines successfully launch B cell response in humans. DOI: 10.1126/science.adh3456

• Immunity. (2025). Stepwise immunization strategy induces HIV-neutralizing antibodies in macaques. DOI: 10.1016/j.immuni.2025.04.006

• The Lancet Microbe. (2025). Phase 1 trial of HIVconsvX shows robust T-cell immunity in African adults. DOI: 10.1016/S2666-5247(25)00123-4

• Reuters Health. (2025). Novel approach to HIV vaccine shows early promise. Reuters

• Scripps Research. (2025). IAVI and Scripps Research confirm germline-targeting strategy with mRNA in humans. Scripps News

• News-Medical.net. (2025). HIV vaccine study marks breakthrough in targeting broad immune responses.

• Biotech Reality. (2025). HIV vaccine trial success: Scripps and IAVI use mRNA to target bnAbs. Biotech Reality

• The Atlantic. (2025). HIV’s Most Promising Breakthrough Has Taken a Hit.

Assessed and Endorsed by the MedReport Medical Review Board