A malaria vaccine booster from the University of Oxford has delivered impressive phase 2b results, with a high efficiency level maintained a full year following an initial regimen of three-shots. This disease area has seen researchers struggle to develop consistently effective vaccines and therapies, so the new vaccine r21/Matrix-M is turning heads. Designed and honed by an Oxford team, it also integrates Novavax's proprietary saponin-based Matrix-M adjuvant. A phase-3 trial is expected to position the shot for large-scale population use by next year.
The World Health Organization (WHO) reports that there were over 240 million cases of malaria worldwide in 2020, with areas such as sub-Saharan Africa, Asia, and the Amazon basin, among other tropical regions, hit the hardest. GSK’s Mosquirix, despite its widespread availability, has shown a flagging efficacy rate, and has only prevented under 40% of malaria cases in children.
R21, in comparison, saw 77% efficacy in its year-long 2b trial of 450 children. This is a milestone—the first time a malaria shot in a controlled trial has reached (and even surpassed) the WHO’s 75% efficacy threshold. Phase 2b continuation is encouraging as well, with an efficacy of 80% seen in a higher-dose adjuvant group and 70% in a lower-dose group a year after the first three-pronged regimen.
“We are delighted to find that a standard four-dose immunization regime can now, for the first time, reach the high efficacy level over two years that has been an aspirational target for malaria vaccines for so many years,” said Adrian Hill, co-author of the paper and director of the University of Oxford’s Jenner Institute.