Oct 5, 2026 · 19 min · 12 segments
For decades, scientists pursued one goal: a vaccine that could prevent the disease. But malaria is caused by a complex parasite, making vaccine development far more challenging than for most…
Adrian HillGuest
Chris SmithHostMarishka Suben
You can see them down a typical microscope, but the malaria parasite is huge in relative terms, around about 1,000 times bigger than a virus.
So why is that a problem? Well, to make a, a vaccine against most bugs, we need to pick part of the composition of the virus or the bacterium, or in this case the parasite, and make a vaccine from that.
And what malaria has is thousands of genes, whereas a virus like COVID has about 10, so we have to pick out the right one and get it to work, and believe me, most of those components don't work.
What iterations have happened then? What did they do in 1908, and what have they done since? And how far has the bar moved?
You could grow it in a complex way, and people did grow it and kill the microbe, the malaria itself, and inject it into initially animals and then safely into humans.
So people knew what this looked like, and ever since we've been diagnosing malaria with a microscope, looking at it, and in newer ways more recently, but it's, uh, been difficult to get malaria vaccines to work because using the whole microbe doesn't always work.
In fact, you have to dissect out a piece of the parasite that makes a very strong immune response that will stop you getting malaria.
Is part of the challenge that it lives, being a parasite, for a lot of the time inside our own cells, and in that respect, it's already hidden from the immune system?
What's unusual about malaria is it infects your blood cells, so you can take a tiny drop of blood.
You don't have to go to the throat like you would with, say, a flu infection, and you can see the malaria parasites.
So when we, you know, find a child coming in with a fever and sometimes drowsy and not very well at all, uh, in an African country with a lot of malaria, a malaria test is often the very first one you do because that's the disease that a one-year-old is, is most likely to have.
After the initial attempts to vaccinate by using the whole organism, what steps were then taken? What did they start to do next to, to try to, to get something that was going to work?
Well, that work started much later than in around about the 1970s and 1980s, when we could actually manufacture the many components that make up the malaria parasite.
And that involved biotechnology, identifying a target antigen, if you like, from the thousands that malaria has, trying those in animal models of malaria and looking for ones that might protect humans as well.
And, and that took decades again until we had vaccines around about the late 1990s, uh, early 2000s, that were giving some efficacy in, in animal models, looked safe in clinical trials, but they really weren't effective enough to, uh, start using or, or licensing.
You can see them down a typical microscope, but the malaria parasite is huge in relative terms, around about 1,000 times bigger than a virus.
So why is that a problem? Well, to make a, a vaccine against most bugs, we need to pick part of the composition of the virus or the bacterium, or in this case the parasite, and make a vaccine from that.
And what malaria has is thousands of genes, whereas a virus like COVID has about 10, so we have to pick out the right one and get it to work, and believe me, most of those components don't work.
What iterations have happened then? What did they do in 1908, and what have they done since? And how far has the bar moved?
You could grow it in a complex way, and people did grow it and kill the microbe, the malaria itself, and inject it into initially animals and then safely into humans.
So people knew what this looked like, and ever since we've been diagnosing malaria with a microscope, looking at it, and in newer ways more recently, but it's, uh, been difficult to get malaria vaccines to work because using the whole microbe doesn't always work.
In fact, you have to dissect out a piece of the parasite that makes a very strong immune response that will stop you getting malaria.
Is part of the challenge that it lives, being a parasite, for a lot of the time inside our own cells, and in that respect, it's already hidden from the immune system?
What's unusual about malaria is it infects your blood cells, so you can take a tiny drop of blood.
You don't have to go to the throat like you would with, say, a flu infection, and you can see the malaria parasites.
So when we, you know, find a child coming in with a fever and sometimes drowsy and not very well at all, uh, in an African country with a lot of malaria, a malaria test is often the very first one you do because that's the disease that a one-year-old is, is most likely to have.
After the initial attempts to vaccinate by using the whole organism, what steps were then taken? What did they start to do next to, to try to, to get something that was going to work?
Well, that work started much later than in around about the 1970s and 1980s, when we could actually manufacture the many components that make up the malaria parasite.
And that involved biotechnology, identifying a target antigen, if you like, from the thousands that malaria has, trying those in animal models of malaria and looking for ones that might protect humans as well.
And, and that took decades again until we had vaccines around about the late 1990s, uh, early 2000s, that were giving some efficacy in, in animal models, looked safe in clinical trials, but they really weren't effective enough to, uh, start using or, or licensing.
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