The World Health Organization (WHO) on Monday put its weight behind a new malaria vaccine. Referred to as R21/Matrix-M, the inoculant is inexpensive to make and has been proven effective in regions of high transmission. It will be rolled out next year alongside an existing vaccine to immunize larger swaths of Africa’s vulnerable population, particularly children.
As its name suggests, R21/Matrix-M comprises two parts. The first is R21, an antigen developed by the University of Oxford and produced at scale by the Serum Institute of India. When a mosquito carrying the malaria parasite bites someone, the parasite enters the person’s bloodstream, where it begins a transformation so complex it has complicated the vaccine development process for over a century. At the start of this shapeshifting scheme, the parasite becomes a sporozoite. This effectively kicks off the infection process, leading to the disease we’ve come to refer to as malaria.
R21 specifically targets the parasite’s sporozoite stage, allowing the body ample opportunity to fend off infection. Matrix-M, an adjuvant developed by the biotechnology company Novavax, boosts the body’s immune response to give it a better chance at eliminating the parasite. The result is a vaccine with up to 75% efficacy, according to preliminary findings from a phase IIb trial still under peer review.
The WHO said the R21/Matrix-M will be rolled out alongside the current standard malaria vaccine, RTS,S/AS01. While the WHO notes the two vaccines have not been tested “head-to-head,” R21/Matrix-M is said to be cheaper and easier to manufacture, as it uses smaller doses and a “simpler” adjuvant than RTS,S/AS01. The Serum Institute of India—the world’s largest vaccine manufacturer—expects to produce more than 100 million doses per year, with plans to double its output.
“As a malaria researcher, I used to dream of the day we would have a safe and effective vaccine against malaria. Now we have two,” WHO director-general Dr. Tedros Adhanom Ghebreyesus said in the organization’s release. “Demand for the RTS,S vaccine far exceeds supply, so this second vaccine is a vital additional tool to protect more children faster, and to bring us closer to our vision of a malaria-free future.”
