What are cancer vaccines?

In this explainer episode, we’ve asked Dr Antonio D'Alessio, Medical Oncologist at Guys and St Thomas Foundation Trust, to explain cancer vaccines and how they work.

You can also find a series of short videos explaining some of the common terms you might encounter about genomics on our YouTube channel.

If you’ve got any questions, or have any other topics you’d like us to explain, let us know on [email protected].

You can download the transcript or read it below.

Florence: What are cancer vaccines and how do they work? My name is Florence Cornish, and today I'm joined by Antonio D’Alessio, who is a medical oncologist ay Guy's and St Thomas' Foundation Trust and King's College. And he's going to be telling us much more about the topic.

So Antonio, before we get into cancer vaccines, I wanted to first ask you about cancer. I know it's a pretty broad term, and it refers to the uncontrolled growth of cells in the body, but maybe it would be helpful for you to explain a little bit more about what cancer actually is, like what that term means, especially for listeners out there who might not have that scientific background.

Antonio: Yeah, of course. And first of all, thanks for inviting me today. Well, that's a big question. The point is that we know that in our bodies there are billions of cells, and all of these cells, they divide, they do their job, and they know when to die on schedule. The point is that sometimes there are cells that ignore this instruction and just keep reproducing and growing, and this is when cancer grows.

Our bodies have systems, which is the immune system, to recognize when this happens so that the immune system can recognize the cancer cells that are growing too much. They attack them and destroy them. But unfortunately, sometimes cancer is quite clever, they manage to escape from the immune system and starts growing without control, and that's when cancer starts.

Florence: And so, what are the standard treatments that we use for cancer at the moment?

Antonio: Well, broadly speaking, I would say that we have three types of cancer treatments. One, it's surgery, where we just cut the cancer out. Then we have radiotherapy, where we basically induce targeted damage to the cancer. And then we have a very broad umbrella term that is systemic therapy.

Systemic therapies can be chemotherapy, can be targeted therapies, and that can be immunotherapy. In particular, immunotherapy is quite exciting because over the past 20 years, we have learned how to boost the immune system of patients, so that's the white blood cells, the immune system of patients that can recognize cancer cells and attack them.

Sort of imagine that cancers hide behind an invisibility cloak, and immunotherapy helps unveil the cancer so that the immune system can recognize the cancer again and attack it. And vaccines and cancer vaccines are part of this family of immunotherapy drugs.

Florence: Yeah so speaking about that, I think lots of listeners might have heard of the term cancer vaccine before, obviously, its the topic of this episode.

And I think the term cancer vaccine sounds very interesting and promising, but also maybe a little bit intimidating as well. So maybe you could tell me more about what a cancer vaccine is kind of at the most basic level.

Antonio: Well, cancer vaccine is a vaccine, and we have received so many vaccines in our lives that our body basically has learnt already how to process a vaccine.

Imagine a vaccine as a wanted poster. So, we give the body the instructions to recognise something that shouldn't be there, and the immune system knows how to do it. So, the job of the immune system is to recognize strangers in our bodies - that can be microbes, bacteria, viruses, and also cancers.

And sometimes with a vaccine, we sort of help the immune system to do its job a bit better. And with vaccines, we provide the instructions to recognize these strangers in our body and help the immune system to, to get rid of them. And in particular, for cancer vaccines, we have different types of cancer vaccines.

There's a family of cancer vaccines that are called preventative, where we can try to give a vaccine even before the cancer develops to reduce the risk that the cancer develops. And, this is more early in the development.

While we have, another family of cancer vaccine, which are mostly mRNA cancer vaccines that are called therapeutic. So these are cancer vaccines that are given to patients who already have cancer, maybe who had the surgery for their cancers, so that the aim of the cancer vaccine is to boost immune system and reduce the chances that the cancer comes back after surgery, or, help other types of immunotherapy work better together with vaccine against the cancer.

Florence: So, I think for me at Genomics England, the mRNA cancer vaccines are probably most relevant to the work that we do here as an organization. Could you explain a little bit more about how those ones work specifically?

Antonio: Yeah, that's an exciting field, right? The mRNA vaccine. So, let's split this into different words, mRNA and vaccine.

We have just covered what vaccine means. We just have to think mRNA as just instructions. So we give the body of the patients the instruction to recognize the cancer. And the mRNA is basically the instruction for the immune system to recognize some of the proteins that are expressed on the cancer cells, so that's the white blood cells, the own white blood cells of the patients that can be more alert and identify the cancer cells if they are around.

And in particular, imagine when we give the mRNA vaccine, it's like we are giving the picture of a suspect to the police, right? The police is the immune system of the patients, and the suspect is the cancer.

And so, the immune system, so the police of our body, can go around the body, can go around the bloodstream, can go around the organs, and if they see the suspect, they are, they are already alerted, and they can tackle it, attack it, and destroy it before it develops into, into a cancer that can be seen on the scans.  

Florence: And are these types or other types of cancer vaccines being used in the clinic at all in real medical settings already?

Antonio: Well, I wouldn't say that we are using that in clinical practice, but probably in the future we will, and we are working hard to make sure that we will be able to use cancer vaccine for our patients.

At this stage, we are using cancer vaccines as part of clinical trials, and these clinical trials cover different types of cancer types, different types of setting, together with other drugs or given alone after surgery, for instance. And the NHS England, Genomics England and NIHR, they launched this massive infrastructure that is called the Cancer Vaccine Launchpad.

And it is aimed specifically to match the NHS cancer patients with personalized mRNA vaccine trials, so that once we have the results of those trials and we are ready to deploy it in clinical practice, then we already have the infrastructure to do that promptly, hopefully in the next future.

Florence: Mm-hmm. Yeah, so do you see a future where cancer vaccines are used in routine care?

Antonio: Well, we are working towards that. And I, and I do see a future where we're going to use that. I don't know when. Probably it will take still a few years.

But the, for example, in the UK and in England in particular, we have a national cancer plan, and the national cancer plan for this year has identified cancer vaccine as a top priority for our health system.

And this is because this is a technology that can be scalable, that can be widely deployed once it's demonstrated to be working. And at this stage, there are still some open questions, like which cancer types in which setting, which patients would benefit from it.

But once we address these open questions in clinical trials, then I do believe that we'll be able to use that in the, in the future.

Florence: I think we'll finish there. Thank you so much, Antonio, for coming on and for taking the time to talk to us.

Antonio: Thank you Florence, and thank you for the invite.

Florence: If listeners want to hear more explainer episodes like this, you can find them on our website at www.genomicsengland.co.uk or wherever you get your podcasts.

Thank you for listening.