Researchers from the University of Oxford and their partners have reported that a malaria vaccine they are developing has proved to be 77% effective in early trials.
The findings of the Phase IIb randomised, controlled, double-blind trial, posted on SSRN/Preprints with The Lancet, show the candidate malaria vaccine, R21/Matrix-M, demonstrated high-level efficacy over 12-months of follow-up, and is the first to meet the World Health Organization’s (WHO) Malaria Vaccine Technology Roadmap goal of a vaccine with at least 75% efficacy.
The researchers from the university’s Jenner Institute are supported by the NIHR Oxford Biomedical Research Centre (BRC).
The trial was conducted in Burkina Faso. There were 450 participants, aged 5-17 months from 24 villages in the Nanoro area of the country.
The participants were split into three groups, with the first two groups receiving the R21/Matrix-M (with either a low dose or high dose of the Matrix-M adjuvant) and the third, a rabies vaccine as the control group. Doses were administered from early May 2019 to early August 2019, largely prior to the peak malaria season.
The researchers report a vaccine efficacy of 77% in the higher-dose adjuvant group, and 71% in the lower dose adjuvant group, over 12 months of follow-up, with no serious adverse events related to the vaccine noted.
Following these results, the Phase IIb trial, which was funded by the EDCTP2 programme supported by the European Union (grant number RIA2016V-1649-MMVC), was extended with a booster vaccination administered prior to the next malaria season one year later.
There were229 million cases of clinical malaria reported in 2019. The WHO estimates that malaria causes over 400,000 deaths around the world each year, and says that progress in reducing malaria mortality has stalled in recent years. Most deaths are amongst children in Africa where very high transmission rates are found in many countries.
Over 100 malaria vaccine candidates have entered clinical trials over recent decades but none has shown the >75% efficacy targeted by the WHO.
Recruitment has now started for a Phase III licensure trial to assess large-scale safety and efficacy in 4,800 children, aged 5-36 months, across four African countries.
Professor Adrian Hill (left), Director of the Jenner Institute and the Oxford BRC’s Theme Lead for Vaccines, said: “These new results support our high expectations for the potential of this vaccine, which we believe is the first to reach the WHO’s goal of a vaccine for malaria with at least 75% efficacy.
“With the commitment by our commercial partner, the Serum Institute of India, to manufacture at least 200 million doses annually in the coming years, the vaccine has the potential to have major public health impact if licensure is achieved.”
Lynsey Bilsland, from Wellcome, which helped fund the research, said: “Despite global efforts against malaria, too many lives are still lost to this disease, especially babies and young children. Vaccines could change this. This is an extremely promising result showing high efficacy of a safe, low-cost, scalable vaccine designed to reach the huge numbers of children who are most at risk of the devastating impact of Malaria. Whilst further studies are required, this marks a significant and exciting step forward on an critical global health challenge.”