Phase 3 trial data confirm efficacy and safety profile of R21/Matrix-M malaria vaccine in African children

Phase 3 trial data results of The R21/Matrix-M vaccine developed by Oxford University and Serum Institute of India, leveraging Novavax’s Matrix-M adjuvant has confirmed high efficacy and supported regulatory approvals and licensure in several African countries. The R21/Matrix-M vaccine was designed in 2011 as a potential improvement on the RTS, S/AS01 malaria vaccine designed in the 1980s. A phase II trial in Burkina Faso, reporting in 2021, was the first to show that R21/Matrix-M could reach the WHO-specified target of 75 per cent efficacy in African children. Recent WHO endorsement will lead to the initial rollout of R21/Matrix-M in the coming months. The new results are published in The Lancet.

A press statement informed, “The trial investigators immunised over 4800 young children in a trial in Burkina Faso, Kenya, Mali and Tanzania and found on average 78 per cent vaccine efficacy over the first year of follow-up across all sites in the 5-17-month-old age group, the age range group which is studied for most malaria vaccines. Efficacy over this period was broadly similar across sites and in different transmission settings. Safety data from the trial have been reassuring with no serious adverse events linked to immunisation. No other vaccine has reported over 55 per cent efficacy in the same age group. A booster dose at a year maintained good efficacy over the following 6-12 months. The vaccine also reduced infection rates in children measured at 12 and 18 months after vaccination suggesting a potentially beneficial effect in reducing malaria transmission.”

It added, “R21/Matrix-M vaccine was well tolerated, with injection site pain and fever as the most frequent adverse events. Number of adverse events of special interest and serious adverse events did not significantly differ between the vaccine groups. There were no treatment-related deaths.”

Significantly increased immune responses to the R21/Matrix-M vaccine and slightly higher vaccine efficacy were observed in 5-17-month-olds compared to 18-36-month-olds malaria vaccines, supporting planned vaccine deployment initially from five months of age in young African children.

The vaccine is licensed to the Serum Institute of India (SII). Matrix-M adjuvant is manufactured by Novavax AB and provided to Serum Institute of India for formulation into the final vaccine drug product.