Malaria booster vaccine shows durable high efficacy in African children, meeting WHO-specified 75% efficacy goal

8 September 2022

Researchers from the University of Oxford and their partners have today reported new findings from their Phase 2b trial following the administration of a booster dose of the candidate malaria vaccine, R21/Matrix-M™ – which previously demonstrated high-level efficacy of 77% over the following 12 months in young west African children in 2021.

In their findings (reported in The Lancet Infectious Diseases), they found that a vaccine booster dose at one year following a primary three-dose regime maintained high efficacy against malaria, and continued to meet the World Health Organization’s Malaria Vaccine Technology Roadmap goal of a vaccine with at least 75% efficacy.

The authors report from a Phase IIb randomised, controlled, double-blind trial conducted at the Clinical Research Unit of Nanoro (CRUN) / Institut de Recherche en Sciences de la Santé (IRSS), Burkina Faso. A total of 450 participants aged five to 17 months were recruited from the catchment area of Nanoro, with 409 receiving the booster.

The participants were randomly assigned to 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) vaccine as a booster and the third a rabies vaccine as the control group. Each child received the same booster vaccination as their primary series of vaccinations. Doses were administered in June 2020, largely prior to the peak malaria season.

The researchers report a vaccine efficacy of 80% in the higher-dose adjuvant group, and 70% in the lower dose adjuvant group, over 12 months of follow-up. Antibody levels were restored to similar levels as those following the primary vaccinations 28 days after the booster doses were administered. No serious adverse events related to the vaccine were noted.

Halidou Tinto, Professor in Parasitology, Regional Director of IRSS in Nanoro, and the trial Principal Investigator, said: ‘It is fantastic so see such high efficacy again after a single booster dose of vaccine. We are currently part of a very large phase III trial aimed at licensing this vaccine for widespread use next year.’

Professor Adrian Hill, the University of Oxford’s Director of the Jenner Institute and Lakshmi Mittal and Family Professor of Vaccinology, and co-author of the paper, said: ‘We are delighted to find that a standard four dose immunisation 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.’

The R21/Matrix-M™ malaria vaccine candidate created by the University of Oxford includes Novavax' proprietary saponin-based Matrix-M adjuvant and is licensed to Serum Institute of India.
The trial – funded by the EDCTP2 programme supported by the European Union (grant number RIA2016V-1649-MMVC) as well as the Wellcome Trust and NIHR Oxford Biomedical Research Centre – has been extended for another two years to assess if further booster doses will be necessary to maintain high efficacy over time.

Results from the key ongoing Phase III licensure trial to assess large-scale safety and efficacy in 4,800 children aged five to 36 months across four African countries, are also expected later this year.

Gareth Jenkins, Director of Advocacy at Malaria No More UK said: ‘Today’s R21 vaccine results from Oxford’s renowned Jenner Institute are another encouraging signal that, with the right support, the world could end child deaths from malaria in our lifetimes.
‘But for new British inventions to achieve their potential, British leadership must continue, not least at the imminent US-hosted Global Fund to Fight AIDS, Tuberculosis and Malaria replenishment conference this September.
‘This will be the new PM’s first foreign policy test - for the sake of millions of children’s lives, global health security, and British relations with its closest ally, it’s a test they cannot fail.’

Notes for editors

For further information or to request an interview with the researchers, please contact: [email protected] or call 01865 280528.

Link to the paper (goes live only after embargo lifts) - https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(22)00442-X/fulltext

Video interviews with key malaria scientists, including Director of the Jenner Institute Adrian Hill and Clinical Research Fellow Mehreen Datoo, are also available at the links below:
Prof Hill – https://vimeo.com/oxforduni/download/738945352/7181946371
Dr Datoo – https://vimeo.com/oxforduni/download/738945456/fff81275fa
Please contact the News Office for the Password.

About malaria
The World Health Organisation (WHO) estimates that malaria caused over 640,000 deaths in 2020 and 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.
An estimated 241 million cases of clinical malaria were reported in 2020. Current malaria control measures include the use of insecticide treated bed net, insecticide spraying and seasonal malaria chemoprevention where drugs are administered monthly to children at time of highest transmission. No vaccine has been licensed for widespread use although efforts to develop vaccines have spanned over 50 years.
Over 100 malaria vaccine candidates have entered clinical trials over recent decades but none has previously shown the >75% efficacy targeted by World Health Organization’s Malaria Vaccine Technology Roadmap. It is likely that an effective vaccine could add to the current control measures and have significant impact. Vaccines could have many applications: reduction of disease and death in malaria endemic areas; contributions to malaria elimination and eventual eradication; protection of malaria-naïve travellers to malaria-endemic regions.

About the Jenner Institute
The Jenner Institute is based within the Nuffield Department of Medicine, University of Oxford, and is headquartered at the Old Road Campus Research Building, in Headington, Oxford. The Jenner Institute also supports senior vaccine scientists, known as Jenner Investigators, within many other departments across the University of Oxford, as well as externally within The Pirbright Institute and the Animal and Plant Health Agency.
The Jenner Institute brings together investigators who are designing and developing numerous vaccines to generate an exceptional breadth of scientific know-how and critical mass, whilst still allowing the individual investigators to remain independent and accountable to their funders and stakeholders.
The Jenner Institute is supported by the Jenner Vaccine Foundation, a UK registered charity and is advised by the Jenner Institute Scientific Advisory Board.

About the University of Oxford
Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the sixth year running, and number 2 in the QS World Rankings 2022. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer.
Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions.
Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 200 new companies since 1988. Over a third of these companies have been created in the past three years. The university is a catalyst for prosperity in Oxfordshire and the United Kingdom, contributing £15.7 billion to the UK economy in 2018/19, and supports more than 28,000 full time jobs.

About Novavax
Novavax, Inc. (Nasdaq: NVAX) is a biotechnology company that promotes improved health globally through the discovery, development and commercialization of innovative vaccines to prevent serious infectious diseases. The company's proprietary recombinant technology platform harnesses the power and speed of genetic engineering to efficiently produce highly immunogenic nanoparticles designed to address urgent global health needs. The Novavax COVID-19 vaccine (NVX-CoV2373) has received conditional authorization from multiple regulatory authorities globally, including the European Commission and the World Health Organization. The vaccine is also under review by multiple regulatory agencies worldwide. In addition to its COVID-19 vaccine, Novavax is also currently evaluating a COVID-seasonal influenza combination vaccine in a Phase 1/2 clinical trial, which combines NVX-CoV2373 and NanoFlu, its quadrivalent influenza investigational vaccine candidate. These vaccine candidates incorporate Novavax' proprietary saponin-based Matrix-M™ adjuvant to enhance the immune response and stimulate high levels of neutralizing antibodies.

About Serum Institute of India Pvt. Ltd.
Driven by the philanthropic philosophy of affordable vaccines, Serum Institute of India Pvt, Ltd. is the world's largest vaccine manufacturer by number of doses produced and sold globally (more than 1.5 billion doses), supplying the world's least expensive and WHO-accredited vaccines to as many as 170 countries. It was founded in 1966 with the aim of manufacturing lifesaving immunobiological drugs including vaccines worldwide. With a strong commitment towards global health, the institute's objective has been proliferated by bringing down the prices of newer vaccines such as such as Diphtheria, Tetanus, Pertussis, Hib, BCG, r-Hepatitis B, Measles, Mumps and Rubella vaccines. SII is credited with bringing world-class technology to India, through its state-of-the-art equipped multifunctional production facility in Manjari, Pune; association with Zipline and government agencies to transform emergency medicine and critical care along with spearheading the race of vaccine development against the COVID-19 pandemic.

About the Clinical Research Unit of Nanoro (CRUN), Burkina Faso.
The CRUN is a specialized unit of the Institute for Health Sciences Research (IRSS). This is one of the four research institutes belonging to the Burkina Faso National Research Center for Sciences and Technology (CNRST) from the Ministry of Higher Education, Research and Innovation. It was created in 2008 to provide a much-needed Good Clinical Practices (GCP) compliant trial platform with the mission to provide evidence-based information for the health care of populations living in tropical countries. The CRUN currently provides a readily available platform to conduct research at high standard level of quality. Its research activities are mainly focused on malaria research, but other topics including febrile illnesses and cardiometabolic diseases are becoming of more important public health concern in the last decade.

About Malaria No More
Malaria No More is a UK charity determined to end malaria by inspiring the UK public, businesses and government to fight for a malaria-free world.
www.malarianomore.org.uk / @malarianomoreuk