The co-inventor of a vaccine that could eradicate malaria has said he hopes it could be approved by as early as next year after the latest trial results were successful.
Professor Adrian Hill, co-creator of the AstraZeneca Covid vaccine, said it was “the best [malaria] vaccine yet”. He has previously said he believes R21 could help to reduce deaths from the disease by 70% by 2030 and eradicate it by 2040.
But speaking as the success of the R21 vaccine tests were revealed, Hill, director of Oxford University’s Jenner Institute, said it would be tragic if Britain cut funding just as scientists were poised to make “a real impact” against malaria. He has implored the new British prime minister Liz Truss not to squander cutting-edge UK innovation by “turning off the taps” on global health funding.
Results from testing in Burkina Faso showed that R21 – already shown to be 77% effective after the initial doses – maintains its high efficacy after a single booster jab.
Q&AMalaria vaccines
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For about a century, scientists have been trying to find an effective vaccine against malaria. It has not been easy. There have been about 140 vaccine candidates and, so far, only one – GSK’s RTS,S – has been approved for widespread use. From next year, it is hoped, there will be another, named R21, courtesy of Oxford University.
In contrast to a relatively simple virus such as Covid-19, the malaria parasite is highly complex and, crucially, much bigger. “With malaria there are thousands of potential targets,” says Katie Ewer, professor of vaccine immunology at Oxford’s Jenner Institute.
So how does the Oxford vaccine work? Ordinarily, once a mosquito has bitten someone, the malaria parasite travels from their skin through the lymphatic system to the blood and finally to their liver, where it causes the infection that makes them ill.
Many previous vaccines have tried to target the parasite when it is in the blood, but by then, says Ewer, “that’s a very, very tall order.” What R21 does is target the parasite early in its lifecycle, just after a person has been bitten by a mosquito and before they get sick.
“R21 is trying to block the parasites before they get to your liver and set off infection,” says Ewer. “And that’s the mechanism for how it works.
"By targeting the earlier stage of the lifecycle," she adds, "there are fewer parasites for the vaccine to mop up, and there’s less diversity in the parasite at that stage as well.”
Lizzy Davies
Researchers hope that the vaccine could be approved by the World Health Organization next year, assuming a larger ongoing trial throws up no unexpected problems.
But Hill also cautioned that getting the vaccine into the arms of tens of millions of African children who most need it would be a challenge without funding.
The body that provides more than half of all financing for the world’s malaria programmes, the Global Fund to Fight Aids, Tuberculosis and Malaria, has warned that unless it receives significantly more money from leading donor countries such as the UK at its pledging conference this month, it will not be able to get the fight against those diseases back on track after the Covid pandemic.
The UK has not yet said what it will pledge in New York, but the fund is thought to have asked for about £1.8bn. As foreign secretary, Truss outlined a strategy for overseas aid marked by an overall spending reduction and a retreat from the funding of multilateral organisations like the Global Fund.
“It’s incredibly important that the Global Fund is properly refunded. What they do is absolutely amazing,” said Hill. “I hope the new prime minister will be very keen to recognise the importance of doing what the UK [the fund’s third-biggest donor] has done so well in the past.”
Another British-made malaria vaccine with more modest efficacy levels, GSK’s RTS,S, approved by the WHO last year, is poised to be more widely deployed from next year. “The two leading vaccines in the world for malaria are [from] a UK-headquartered company and a UK university,” Hill said.
“The UK is good at this stuff … It would be tragic if suddenly, as new tools become available, and we can have a real impact – and that’s not hard to see now by getting these [vaccines] out there – if we were to just we turn off the taps on funding. And there is a risk of that.”
Gareth Jenkins, director of advocacy at Malaria No More UK, echoed Hill’s appeal, saying that “for new British inventions to achieve their potential, British leadership must continue”, starting at the Global Fund conference, to be hosted by the US president, Joe Biden.
“This will be the new PM’s first foreign policy test – for the sake of millions of children’s lives, global health security and British relations with its closest ally, it’s a test she cannot fail,” he added.
Scientists have been trying to find a good vaccine against malaria for about a century, with the first clinical trial taking place in the 1940s. The disease kills hundreds of thousands of people every year, mostly children under five in sub-Saharan Africa.
R21, the first malaria vaccine to meet a WHO efficacy target of 75%, is licensed to the Serum Institute of India. It is ready to manufacture at least 200m doses annually from next year if the jab is given the green light after results from the wider trial, expected later this year.
Prof Halidou Tinto, regional director of the health sciences research institute (IRSS) in Nanoro, and the Burkina Faso trial principal investigator, said that while production was not expected to be an issue, the big challenge for poor African countries was how to fund the vaccine’s rollout. “This may be … the issue that could delay the deployment,” he said.
The trial in Burkina Faso involved more than 400 children aged between five and 17 months getting three doses of the vaccine in 2019, followed by a single booster shot 12 months later, largely before the peak of the malaria season.
The results, published in the Lancet Infectious Diseases, show that in those children given a booster shot with a higher dose of an immunity-boosting adjuvant the vaccine proved 80% effective. That figure fell to 70% in those who were given a booster with a lower dose of the adjuvant.
No serious side-effects were noted, researchers said.
A spokesperson for the Foreign, Commonwealth and Development Office said: “As the third largest donor to the Global Fund the UK has invested £4.1bn to date to fight Aids, tuberculosis, and malaria around the world. We will continue to support its vitally important work.”