A new malaria vaccine developed by Britain's University of Oxford is 80% effective in preventing infection, according to trial results published Thursday in The Lancet medical journal. Scientists say it represents a huge breakthrough that has the potential to save millions of lives and eventually eradicate the disease.
The vaccine, named R21/Matrix-M, had already shown encouraging trial results after three primary doses. Maintaining that immunity has always been a big challenge and the latest trial shows that a booster dose is effective, explained Professor Adrian Hill, the director of the Jenner Institute at the University of Oxford and co-author of The Lancet paper.
"The technology has been complex to develop because we need very strong antibody responses to get protection against malaria and those antibodies, like all responses, decline over time," Hill told VOA.
"One of the worries was that this would be short-term protection and only last for a few months. That's definitely not the case with the data we're releasing today," Hill said. "And indeed, 80% efficacy in the second year of follow up after a booster dose is really very encouraging in that respect."
The latest phase II trial involved 450 children between 5 and 17 months old, recruited from the Nanoro region in Burkina Faso. The results show a higher strength booster dose was 80% effective in preventing malaria infection. No serious side effects were seen.
"This is a parasite we're trying to vaccinate against. It's not a virus. It's got thousands of genes. [So it's] complex to design a vaccine," Hill said. "Over 100 have been in clinical trials and this looks like the best data so far. So we're excited."
The Serum Institute of India, which has produced billions of doses of the Oxford-AstraZeneca COVID-19 vaccine, is producing the R21/Matrix-M malaria vaccine. It has signed an agreement to rapidly scale up production if the vaccine receives World Health Organization (WHO) approval in coming months.
"We're trying to do something similar with malaria, to produce a low-cost vaccine — a few dollars a dose — and to manufacture that really upscale so we can get 100 million doses or more out there as soon as possible," Hill told VOA.
Malaria killed an estimated 627,000 people in 2020, the most recent available data. The majority are children under five years old in sub-Saharan Africa.
The WHO approved the first-ever malaria vaccine in October of last year, called RTS,S. But R21 may offer even greater hope, said Hill.
"A vaccine with high efficacy like this should be able to save hundreds of thousands of lives a year and ultimately millions of lives over the next decade or so," he said. "After we get a vaccine rolled out for that very vulnerable population, we'll be looking at a travelers' vaccine and then we'll be looking at a vaccine that could actually eliminate regionally and eradicate globally this terrible disease."
Results from the ongoing phase III trial involving 4,800 children are due later this year and it's hoped that mass production and rollout can begin in 2023, following WHO approval.