Hopes high new malaria vaccine will 'significantly reduce' deaths

Children under the age of five accounted for about 80 per cent of all fatal cases in Africa

Mosquitos are a carrier of the disease. Photo: CDC / Wikimedia Commons

It is hoped a new malaria vaccine that tackles the infection at a different stage to those currently on offer will “significantly reduce” the number of deaths and severe cases of the disease.

The vaccine – known as RH5.1/Matrix-M – has been shown to be “safe and well tolerated” in clinical trials.

The new injection targets malaria in the “blood stage”, which comes after the plasmodium falciparum parasite that causes the deadliest form of the disease passes through the liver.

Once red blood cells become infected, symptoms such as fever and chills begin and can lead to complications including anaemia and organ failure.

Existing licensed vaccines target the liver stage of malaria – which is symptomless – and are “very effective” at stopping parasites from getting into the blood, researchers said.

But if some “slip through the net”, existing injections are not effective, experts said.

“Our goal, by targeting the blood stage of the disease with this vaccine, is to significantly reduce the number of severe cases and deaths,” Angela Minassian, associate professor in the department of biochemistry, who leads the clinical blood-stage malaria vaccine programme at the University of Oxford, said.

“The current licensed vaccines, R21/Matrix-M and RTS,S/AS01, target the liver stage of the parasite and are very effective at stopping parasites from getting into the blood.

“However, if they fail and parasites slip through the net, the disease will develop as these approved vaccines have no activity against malaria in the blood.

“Adding RH5.1/Matrix-M to these licensed vaccines should provide a vital second line of defence, achieving even higher levels of protection.

“Importantly, our study has provided the first real-world data to show that this type of vaccine works by reducing the level of parasites in the blood.”

Children participate in trials

The phase 2b trial involved 361 children, split into two groups.

One group received three doses of the RH5.1/Matrix-M vaccine and the other three doses of a rabies vaccine.

Those who had the RH5.1/Matrix-M developed high levels of antibodies against the malaria parasite, the study found.

This was more pronounced among children who had their vaccine as a newborn and at one and five months of age compared with those who had theirs as newborns and at one and two months.

Simon Draper, professor of vaccinology and translational medicine in the departments of paediatrics and biochemistry at the Kavli Institute of Nanoscience, invented the RH5.1/ Matrix-M vaccine.

“The development of an effective blood-stage malaria vaccine has proved to be an exceptionally tough scientific challenge, with previous clinical trials over a number of decades reporting no or minimal efficacy,” he said.

“These first efficacy results for a new generation of blood-stage vaccine candidates targeting the RH5 malaria protein are hugely encouraging, and represent a major milestone for the malaria field.

“We now have the exciting opportunity to test the new RH5.1 blood-stage vaccine in combination with the approved liver-stage vaccines, with the goal of developing a second-generation product that can offer very high-level efficacy against malaria disease in young African children.”

“Frequent malaria infections can impair a child’s growth and development,” Halidou Tinto, a professor of parasitology and regional director of the Institut de Recherche en Sciences de la Sante, in Burkina Faso, said.

“This trial has shown that RH5.1/Matrix-M is safe and well tolerated. No serious side effects were reported, and further stages of the trial and follow-on trials will continue to monitor the vaccine’s longer-term safety and efficacy.”

UK announces £5m programme

On Wednesday, the UK government announced a £5 million ($6.4m) programme with the RBM Partnership to End Malaria set to renew the push to end the epidemic by 2030.

The UK’s new partnership will support RBM as it brings global leaders together in the fight against malaria. This includes tackling resistance to malaria treatments and supporting efforts to control malaria in four countries: Cameroon, Nigeria, Tanzania and Uganda.

Tackling malaria will also help unlock growth in the Global South. Analysis shows reducing malaria cases by 90 per cent by 2030 could boost GDP by over $142 billion in malaria-endemic countries.

Malaria vaccine – in pictures

“Thanks to the expertise of British scientists and the efforts of partners across the world, we have shown that the malaria epidemic can be ended,” British Minister for Development Anneliese Dodds said.

“But in the Global South, too many are still losing their lives and livelihoods to the disease, with pregnant women and children especially vulnerable.

“The UK is pleased to be partnering with the RBM Partnership to End Malaria, contributing £5 million to re-energise global efforts to tackle the epidemic.

“With the right tools, treatments and leadership, we can get back on track to end malaria, save lives and unlock billions in economic growth.”

The UK’s partnership with RBM solidifies the UK as a crucial partner in global efforts to end malaria. The UK is also a leading supporter of Gavi, the Vaccine Alliance and the Global Fund to Fight AIDS, Tuberculosis and Malaria, and supports research into new tools to prevent and treat malaria.

British scientists helped develop two malaria vaccines which have the potential to save millions of lives, including the RH5.1/Matrix-M injection.

With UK support, Gavi and the Vaccine Alliance are helping roll out the new vaccines in up to 25 countries by 2025, including in Nigeria last week.

This week, Minister Dodds is in Malawi, one of three countries where the RTS,S vaccine was shown to reduce child mortality by 13 per cent.