R21/Matrix-M malaria vaccine: What it is, and when will it roll out?

The World Health Organisation (WHO) has recommended the R21/Matrix-M malaria vaccine developed by the University of Oxford and the Serum Institute of India following meeting all required safety, quality, and effectiveness standards.

Following a scientific review by the WHO's independent advisory body, the Strategic Advisory Group of Experts (SAGE) and the Malaria Policy Advisory Group (MPAG), the R21/Matrix-M malaria vaccine has been recommended for use. Following this, additional regulatory approvals are expected to follow shortly, and the vaccine doses could be ready to begin a wider roll-out by next year.

The Matrix-M component is a proprietary saponin-based adjuvant from Novavax, licensed to the Serum Institute for use in endemic countries.

Developing the vaccine

The vaccine was developed by the Jenner Institute at Oxford University and the Serum Institute of India with additional support from the European and Developing Countries Clinical Trials Partnership (EDCTP), Wellcome Trust, and the European Investment Bank (EIB).

The R21/Matrix-M malaria vaccine has been licensed for use in Ghana, Nigeria, and Burkina Faso, all three countries in West Africa.

The R21/Matrix-M malaria vaccine is an easily deployable vaccine that can be manufactured at a mass scale with a modest cost, thus helping save and improve the lives of millions of children and their families.

The R21/Matrix-M malaria vaccine recommendation "was based on pre-clinical and clinical trial data, as they showed good safety and high efficacy in four countries, at sites with both seasonal and perennial malaria transmission, making it the world's second-ever WHO-recommended vaccine for preventing malaria in children", stated the University of Oxford.

Phase III clinical trial

The vaccine completed the one-year endpoint in the Phase III clinical trial, which included 4,800 children across Burkina Faso, Kenya, Mali, and Tanzania. The results of the Phase III trial are under peer review before publication.

The University of Oxford stated: "The vaccine was well tolerated with a good safety profile. The efficacy of the vaccine over 12 months was 75 per cent (95 per cent CI 71-79; p<0.001) at sites with high seasonal malaria transmission and 68 per cent (61-74; p<0.001) at sites with more perennial transmission using standard age-based administration."

As there was some waning efficacy over the first year of follow-up at both seasonal and perennial transmission sites, a booster dose restored efficacy at the seasonal sites with a vaccine efficacy over 18 months of 74 per cent.

High vaccine-induced antibody titres were observed in children aged 5–17 months, compared with 18–36 month-olds. The younger age group showed the highest 12-month vaccine efficacy at both seasonal, 79 per cent, and standard sites, 75 per cent (65-83, p<0.001).

In a previous Phase IIb clinical trial, researchers reported a two-year efficacy and showed that a booster dose of R21/Matrix-M maintained high efficacy against malaria and continued to meet the WHO's goal of a vaccine with at least 75 per cent efficacy.

Cost and manufacturing capacity

WHO chief Tedros A Ghebreyesus said that the vaccine will become available by mid-2024, and the doses would cost between $2 and $4.

The Serum Institute has established a production capacity of 100 million doses annually, which will be doubled over the next two years.

Malaria cases

In 2020, 29 of the 85 malaria-endemic countries accounted for 96 per cent of malaria cases. India contributed 1.7 per cent of malaria cases and 1.2 per cent of deaths globally.

According to the estimates of the WHO, India reports around 15 million malaria cases annually, with around 19,500–20,000 deaths.

Between 2019 and 2020, all high-burden to high-impact (HBHI) countries, except India, reported an increase in cases and deaths.

In 2022, there were an estimated 241 million malaria cases globally in 85 malaria-endemic countries, increasing from 227 million in 2019. Most of the cases came from countries in the WHO Africa Region, which accounted for 95 per cent of cases.