Children use a net for protection from malaria and other mosquito-borne diseases. In sub-Saharan Africa, malaria is a leading cause of death for children, underscoring the need for a vaccine.
Photo by Arne Hoel, courtesy World Bank/Flickr Creative Commoms
Adrian Hill, FMedSci, FRCP, FRS, is director of the Jenner Institute and co-director of the Oxford Martin Program on Vaccines at Oxford University. He co-led research on the Oxford-AstraZeneca COVID-19 vaccine. In April, his team announced that a candidate malaria vaccine had achieved a 77% efficacy in early clinical trials. The vaccine is now in Phase III clinical trials involving a larger population and additional benchmarks on safety and effectiveness.
What makes this latest attempt at a malaria vaccine significant?
There is no malaria vaccine licensed in any country, and people have been trying to do this for over 100 years. This has been a tough problem to crack.
This is the first time that any vaccine has reached the level of efficacy that the World Health Organization have specified they would like to see for a vaccine to save lives, particularly for use in children, where the highest disease burden is to be found.
That said, we’re not at 100%. But then, no vaccine is 100% effective. Getting to 77% is a substantial step forward.
What’s so exciting to me is people really understand now that you can move vaccine development forward much more quickly than it generally happens, which certainly has implications for disease in low-income countries.
Why shouldn’t we have a big push on malaria? On TB? On HIV? We’ve made a big effort, it’s been really tough. But there are new opportunities now and new technologies, and certainly faster ways of making vaccines that could make a real difference to the lives of many people.
If all goes well in further trials, when do you expect the vaccine to be distributed?
We are targeting 2023. That would be quite quick for a Phase III trial. Very often in normal time, you take that long to get your Phase III trial done, put all the results together, assemble a package for regulators, and then (they) take six months to a year maybe to consider it.
A person measures out medication for treatment of malaria in Nigeria in 2008. As many as 1 million people annually die from malaria around the world, according to UNICEF.
Photo by Arne Hoel, courtesy World Bank
Except that’s not what’s happened last year with COVID-19. A lot more people died of malaria in Africa last year than of COVID. But we have to remember that, with malaria, it’s children who are dying. Why would you not want to consider emergency use authorization of a malaria vaccine?
We’ve talked to African regulators and they’re certainly willing to consider it. That’s something we are exploring.
I can’t promise that there will be an emergency use authorization review, even let alone approval. But the question is being asked. This is such a problem in Africa.
Considering the speed of developing COVID-19 vaccines, why has it taken so long to create a vaccine against malaria, which kills so many people annually?
The starting point is a protozoan parasite that is thousands of times larger than a coronavirus. One way of looking at that is the coronavirus has 12 genes; malaria has over 5,000.
It’s technically more complicated, not just because you’re trying to deal with a bigger beast. You have to choose the right antigen or a very small number of antigens from something that has thousands.
There are other things against you. The malaria parasite has four stages to its life cycle, and you can only target one stage at a time.
We are trying to tackle the sporozoite, which is the parasite that mosqui-toes inject into your arm and rushes off to the liver within an hour. That needs a different vaccine.
—Interview conducted, edited and condensed by Aaron Warnick
To read the research findings, visit www.thelancet.com.
- Copyright The Nation’s Health, American Public Health Association
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- What makes this latest attempt at a malaria vaccine significant?
- If all goes well in further trials, when do you expect the vaccine to be distributed?
- Considering the speed of developing COVID-19 vaccines, why has it taken so long to create a vaccine against malaria, which kills so many people annually?