Vaccines have been a game changer in the medical world and human health. They’ve helped protect us from measles, mumps, polio and, most recently, COVID-19. They’ve even eradicated smallpox, one of the deadliest diseases in human history.

It’s an impressive track record, and one that continues to save lives. It also raises an important question: can we use vaccines to tackle cancer?

Traditionally, vaccines have been used to prevent infectious diseases, and they’ve been made from weakened or harmless versions of the virus or bacteria that they’re designed to stop. They teach our immune system how to fight off infections without actually making us ill.

But even though cancer itself isn’t a virus or bacteria, the concept of using vaccines to stop some forms of it isn’t completely new.

Let’s take the HPV vaccine as an example.

So, we know vaccines can stop cancer-causing viruses, but can they fight cancer itself?

Well, the immune system in our bodies is also one of our best defences against cancer. The problem really comes when cancer cells find ways to escape it, which allows them to develop and spread.

Sometimes, the immune system needs a boost. Let's look at how vaccines could provide it.

Protein or peptide vaccines 

These types of vaccines are made from special proteins in cancer cells, or from small pieces of protein (peptides). They aim to stimulate the immune system to attack cancer. Scientists have worked out the genetic codes of many cancer cell proteins, so they can make them in the lab in large quantities. 

DNA and RNA vaccines

DNA and RNA vaccines use bits of genetic material (DNA or RNA) that are usually found in cancer cells. The DNA or RNA is injected into the body, delivering information to the body’s cells and instructing them to make proteins that kick-start an immune response. 

Whole cell vaccines

As the name suggests, these vaccines are made with whole cancer cells, not just specific cell antigens. The cancer cells are extracted and modified in the lab before being injected into the body, where they help show the immune system how to find other cancerous cells.

Scientists can make these vaccines from the patient’s own cancer cells, another person’s cancer cells or cancer cells that were grown in the laboratory.

Dendritic cell vaccines 

Dendritic cells help the immune system recognise and attack abnormal cells. Scientists can use dendritic cells for vaccines by loading them with cancer cell antigens, which they display on their surface like a badge. The vaccine uses that ‘badge’ to stimulate the immune system to attack cancer.

Viral vector vaccines 

Scientists can also modify viruses to deliver cancer antigens into the body. These viral vectors can’t cause serious illnesses, but they do stimulate an immune response, which helps the immune system to recognise and respond to the cancer antigen. 

The COVID-19 pandemic accelerated the production of vaccines - especially those made with mRNA. Their international success has influenced research into cancer vaccines, too.

Messenger RNA (mRNA) is a genetic material in our cells that copies instructions from our DNA and uses them to make proteins that carry out different functions in the body. Unlike traditional vaccines, which use dead or weakened viruses, mRNA vaccines use mRNA with the instructions for making a cancer antigen. When it’s injected, this mRNA guides some of our cells to make harmless antigens, stimulating the immune response.

Part of the allure of mRNA vaccines is their speed and efficiency. To make an inactivated virus vaccine, scientists need to isolate the virus, grow it, inactivate it and formulate it. With mRNA, they only need to get the right sequence of genetic instructions.

Vaccines that use mRNA can also be more specific. Scientists can use mRNA technology to identify a tumour’s unique genetic sequences or mutations. That helps the immune system target cancer cells while avoiding healthy ones. This means side effects in the body are minimal and makes mRNA vaccines an attractive alternative to chemotherapy. 

It took a long time for mRNA to start being used for medicine. Scientists were only able to replicate its structure in a laboratory 20 years after first discovering it in 1961. Then they had to deal with the fact mRNA is notoriously fragile. Delivery it into the body was a huge challenge until 2008, when researchers discovered how to stabilise mRNA in a vaccine.

Even once these biological roadblocks had been cleared, it took the pressure of a pandemic to push mRNA vaccine technology into the mainstream. Before then, it had only been used in clinical trials. 

Now, things are moving much faster. Just a few years on from the first mRNA COVID-19 vaccines, multiple trials for mRNA cancer vaccines are well underway. Dr Heather Shaw from University College London is leading one into a personalised vaccine for treating melanoma.

Patients from across the UK are taking part, and each is receiving a custom-built vaccine made from their unique tumour genetics. These vaccines are combined with immunotherapies once other treatments are complete. Their job is to help the immune system to specifically target any remaining skin cancer cells and stop the cancer returning.

To hear more about Dr Heather Shaw’s research, you can listen to her on our podcast, That Cancer Conversation.

One vaccine alone can’t beat cancer. That’s why we're helping to fund many different types of cancer vaccines, including new types of prevention vaccines, like LungVax and OvarianVax. 

LungVax is the world's first experimental vaccine for preventing lung cancer in people with a high risk of the disease. It uses viral vector technology similar to the Oxford/Astra Zeneca COVID-19 vaccine.

“Our idea for the vaccine came from conversations with the TRACERx team at the Francis Crick Institute and University College London,” says Professor Sarah Blagden, co-founder of the LungVax project. “TRACERx was the first study to track people with lung cancer over time and gave a detailed record of how the cancer cells changed. This helped identify which changes happened first, so we could make the very first inroads into designing a vaccine to stop those early changes from occurring.” 

These early changes are also known as pre-cancers. Pre-cancerous cells have a higher risk of becoming cancerous than other cells, but, for the most part, they don’t cause any problems. 

“Our immune cells are probably already defeating pre-cancers on a daily basis. They recognise if one is starting in our body and send in immune cells to stop it,” says Blagden.

“Our body’s inbuilt defence mechanism is great but imperfect, so some pre-cancers escape detection and grow. The purpose of our vaccine is to give the immune system a reminder of what a pre-cancer looks like, so it’s better at recognising and destroying these abnormal cells as they develop.” 

Cancer prevention is just as important as treatment. But, as Blagden points out, preventative cancer vaccines could be the more efficient option

“Vaccines designed to treat established cancers often cannot work on their own," Blagden explains. "However, we think that pre-cancers may have not yet learned immune evasion and a vaccine may be much more effective, even on its own, at stimulating an immune reaction.”

We recently gave the LungVax team funding to launch a Phase 1 trial of their vaccine, which is expected to begin in summer 2026. Meanwhile, another research group, also based at the University of Oxford is developing OvarianVax, the first vaccine designed to protect high-risk groups from ovarian cancer.

“Thanks to decades of research, scientists have discovered lots of cancer-related antigens, including around 100 associated with ovarian cancer,” explains Professor Ahmed Ahmed, lead for the OvarianVax project. “My team have studied this huge dataset to find the most common antigens that ovarian cells display as they’re starting to become cancerous. OvarianVax will contain a cocktail of these common antigens, giving our immune system a ‘heads up’ as to what early ovarian cancer cells look like.” 

Before they give OvarianVax to anyone at risk of ovarian cancer, Ahmed and his team will test how well it works in the lab. They’ll be using 3D models of fallopian tubes and ovarian tissue to see if the vaccine can help immune cells recognise ovarian cancer antigens and destroy pre-cancerous cells. If the lab tests are successful, the team can begin clinical trials. 

“The success of COVID-19 vaccines has created a huge boost for vaccine research worldwide, including cancer prevention vaccines. Researchers are already creating vaccines to treat advanced cancer. These are promising, but it’s a very complicated area,” says Ahmed. 

“Intercepting the disease before it develops is a completely different situation. At this stage, there’s much less disease in the body and it hasn’t yet manipulated the immune system, so it’s much easier to fight off. I think there’s a lot of potential in preventative vaccines.”