Cancer Vaccines

Where are we?

By Sophie Wedekind

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

Can they do something similar for cancer? 

Many vaccines are 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 illness without actually making us ill.  

Let’s take COVID-19 as an example.

COVID vaccines train the body to make specific anti-COVID antibodies, blood proteins that the immune system uses to recognise and attack infections. This means that if you come into contact with COVID-19 at a later date the immune system knows how to fight it.  

So where does cancer come into this? Well, the immune system in our bodies is one of our best defences against cancer. But cancer cells can find ways to escape it, and when they do that’s when it can develop and spread. Sometimes, the immune system needs a boost. Researchers believe cancer vaccines could be an answer.  

It falls under an umbrella of treatments called cancer immunotherapy, where the immune system is utilised to reduce the size of tumours and treat cancer.   

A history of vaccines and cancer

The concept of using vaccines for cancer isn’t completely new. Over the years scientists have shown associations between certain viruses and increased risk of some cancer types. For example, human papillomavirus (HPV) being a cause of cervical cancer. 

HPV was first linked to cervical cancer in the 1980s. It is an extremely common virus. Around 8 out of 10 people will be infected with HPV at some point in their lives. Not all cases of HPV will end up causing cervical cancer, but it can increase the risk. 

The HPV vaccine is given out in a nationwide programme. Originally, it vaccinated adolescent girls against 2 strains of HPV – HPV 16 and 18. These strains are connected to around 7 in 10 cervical cancer cases. Now, the vaccine extends its protection against 9 strains of HPV and is offered to all children aged 11-13. For those who missed out on receiving it, there is a catch-up programme up to the age of 25. 

Results from a landmark study in 2021 showed the vaccine was effective in reducing cervical cancer risk. In fact, the vaccine was shown to reduce cervical cancer rates by almost 90% in women in their 20s who were offered it at age 12 to 13.  

Similarly, Hepatitis B has been linked to liver cancer, increasing risk by 15-25%. The chance of getting the virus is low in the UK, but if you’re travelling to a country where it is more common, you can get vaccinated. 

However, these are preventative examples – where vaccines are being used to prevent a virus, which in turn reduces cancer risk.   

Developing vaccines against cancer itself is something different. The idea behind these vaccines is that they will be used to treat cancer, rather than preventing it.  

How do cancer vaccines work? 

In the same way traditional vaccines use part of the virus to prevent disease, cancer vaccines use harmless proteins from the surface of cancer cells known as antigens. 

When these antigens are introduced into the body, they should stimulate the immune system to produce antibodies against them, giving it the tools to kill cancer cells. 

But this isn’t straightforward. Tumours are different for every individual, and they have different antigens. So, there can’t be one universal vaccine for cancer – different vaccines will need to be created for different tumour types.  

That’s not the only problem. A lot of the antigens made by tumours can look like the body’s own antigens. Using these in a vaccine could cause the immune system to target healthy cells, which can have dangerous side effects.

Thankfully, researchers have been able to identify a range of tumour-specific antigens, which aren’t found on healthy cells, and tumour-associated antigens, which are present on some normal cells. These antigens are useful markers to help the immune system target cancer cells while leaving healthy parts of the body alone. 

The next step is delivering these antigens into the body. To do that, scientists are trying out lots of different cancer vaccine technologies. 

Types of cancer vaccine 

You can learn more about the different types of cancer vaccine on our About Cancer pages.

Protein or peptide vaccines 

These 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 the 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

Bits of genetic material (DNA or RNA) that are usually found in cancer cells are used for the vaccine. They’re 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

A whole cell vaccines use the whole cancer cell, not just a specific cell antigen, to make the vaccine. The cancer cells are changed in the lab to make them easier for the immune system to find. 

Scientists 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, such as cancer cells. To make the vaccine, scientists grow dendritic cells, a type of immune cell, alongside cancer cells in the lab. The vaccine then stimulates the immune system to attack the cancer. 

Virus vaccines 

Scientists can change viruses in the laboratory and use them as a type of carrier to deliver cancer antigens into the body. They change the viruses so that they cannot cause serious disease. The altered virus is called a viral vector. 

Some vaccines use a viral vector to deliver cancer antigens into the body. The immune system responds to the viral vector. This then helps the immune system to recognise and respond to the cancer antigen. 

How far have we come?

Some types of cancer vaccines are showing more promise than others. Dendritic cell vaccines are already making a real difference to people with cancer. They use a type of immune cell, called dendritic cells to kick-start the immune system.  

These dendritic cells are loaded with cancer antigens and display them on their surface like a badge. This ‘badge’ guides other immune molecules, called T-cells, to target and attack other cells with these antigens.  

Sipuleucel-T (also known as Provenge), was developed for treating prostate cancer and became the first dendritic cell vaccine approved by the Food and Drug Administration in the US in 2010. A clinical trial showed that the vaccine reduced the risk of death by 22.5%. 

Dendritic cell vaccines have the advantage of being very target specific. They're made using the patients’ own cancer cells, allowing the vaccine to be well tolerated with little to no side effects. But the process is costly and slow. 

The main issue of this type of treatment, is that cancer causes a suppressed immune system. This means that cancer can actively stop the immune system from attacking it.  

T-cells have proteins, called checkpoints, which can turn the immune system off when it is no longer needed. But cancer cells interact with checkpoints and tricks the immune system to turn off, preventing an attack.  

Immunotherapy drugs called checkpoint inhibitors turn the T-cells back on and attack cancer cells. While this type of immunotherapy is relatively successful, it doesn’t work for everyone. 

But progress in the field of immunology has significantly increased, thanks to new technologies. 

Learning from COVID-19

The COVID-19 pandemic has accelerated the production of vaccines, specifically mRNA vaccines. Their international success has influenced the direction of research when it comes to cancer vaccines.  

Messenger RNA (mRNA) is a genetic material 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, these 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 an 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 the right sequence of genetic instructions.  

Vaccines that use mRNA can be more specific. Scientists can use mRNA technology to identify all the tumour’s unique genetic sequences or mutations. That helps the immune system spot and target only cancer cells and not healthy ones. Also, side effects in the body are minimal, making mRNA vaccines an attractive alternative to chemotherapy. 

“mRNA vaccines are one of the most exciting research developments to come out of the pandemic, and there are strong hints that they could become powerful treatment options for cancer.”
Dr Iain Foulkes, Executive Director of Research and Innovation at Cancer Research UK

It took a long time for mRNA to start being used in the development of treatments. It was discovered in 1961, but it took another 20 years for scientists to replicate it in the laboratory. It is also notoriously fragile, so delivery 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 into the mainstream.

Meet Infinitopes

Infinitopes was founded in 2021 and since then has made huge strides in the field of cancer immunotherapy. The Cancer Research Horizons spinout is harnessing their Precision ImmunomicsTM to produce the next generation of cancer vaccines. 

“We started to bring all of these things together initially just for a PhD, but it became really clear that this is something that had fundamental promise that we would want to explore,” says Dr Jonathan Kwok, co-founder and CEO of Infinitopes.  

During his PhD, Kwok and his team were comparing a range of viral vector vaccines in mice. And very quickly they found that the mice receiving precise immunomic vaccines had shrinking tumours. 

But what is Precision ImmunomicsTM? 

“What it means is understanding the tumour cell and understanding the immune system’s environment. Then very precisely figuring out what targets the immune system is looking for,” Kwok explains. 

Because that’s the hard thing about tumours, they look just like our cells. But this is where proteins become important. It’s possible to identify individual protein signatures on the tumour cell to tell it apart from healthy cells. And it’s those signatures which help the immune system target the cancer cells. 

This is the foundation of how Infinitopes is developing cancer vaccines.  

Instead of looking at the genetic material of the tumour, they’re looking at the proteins already being made, with the help of AI. 

“So, what we're doing is looking at big pools of patients in specific cancer types to find out which of the targets are going to work in 60 to 70% of patients. And that helps make it not only accurate but affordable too.” 

These therapies hold great promise and potential, but there is still a way to go until they become public treatments.

So, where are we?

Over the past few years, research and clinical trials for cancer vaccines has soared. 

In 2023, the UK government announced it was partnering with BioNTech, who contributed to the development of the Pfizer COVID-19 vaccine to boost research into vaccines for cancer. This year, as a result, we’re seeing a boom of clinical trials taking place across the globe.  

For example, the NHS announced it has treated its first patient in England with a personalised vaccine against their bowel cancer, in a clinical trial part of NHS England’s new Cancer Vaccine Launch Pad. The platform is being led by Professor Gareth Griffiths at our Southampton Clinical Trials Unit.  

Thousands of cancer patients in England are set to gain fast-tracked access to trials of personalised cancer vaccines, following the launch of this world-leading NHS trial ‘matchmaking’ service to help find new life-saving treatments.   

As well as this, recently the UK saw the first participant, Steve Young, for the world's first "personalised" mRNA vaccine against melanoma. Steve had a melanoma growth cut out of his scalp last August and is taking the shot in hopes that it will prevent his cancer from returning.  

And at ASCO 2024, researchers led by a team at New York University combined a vaccine using the same mRNA technology with an established immunotherapy called pembrolizumab. Their early trial results for the first vaccine treatment for the form of skin cancer usually caused by sun damage show that it could halve the risk of patients dying or the disease returning. 

Looking to the future 

When making cancer vaccines, researchers face a lot of challenges. 

Some have already been overcome. Thanks to the discovery of tumour-specific antigens, we already know how to target tumours. But there are also some challenges which are unavoidable, like the length of time it takes to trial and test a vaccine and the need to develop specific vaccines to target different types of tumours.  

However, cancer vaccines have made significant developments recently. The use of mRNA has transformed the typical vaccine timeline to one that is faster and more effective. With the recent launch of various personalised cancer vaccine clinical trials, we could be in store for an influx of cancer vaccines as a new treatment option in the near future.  

A few decades ago, cancer vaccines were science fiction. Now they’re becoming a reality. 
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