‘Great day for science’: WHO recommends development of second malaria vaccine

A key expert advisory group from the World Health Organization (WHO) yesterday recommended approval of the R21/Matrix-M vaccine for use in children at risk of malaria caused by Plasmodium falciparum.

The news marks a major milestone in global efforts to control the disease, with WHO Director-General Tedros Adhanom Ghebreyesus calling the news “a great day for health. A great day for science. A great day for vaccines.” It’s also a great day.”

“The SAGE-MPAG joint recommendation of the R21/Matrix-M vaccine to the World Health Organization represents another important step towards our goal of creating a malaria-free life for every child.”

– David Marlowe, CEO of GAVI

WHO Strategic Joint Expert Group on Immunization (SAGE) and Malaria Policy Advisory Group (MPAG) This makes R21/Matrix-M the second malaria vaccine recommended for use after the approval of the RTS,S/AS01e vaccine in 2021.

Although the two vaccines have not yet been directly compared, Dr. Dyann Wirth, chair of the MPAG panel, noted that “all indications are that they will be very similar” with about 75% efficacy when given to children. Areas of seasonal high and moderate transmission.

increase in supply

Crucially, R21/Matrix-M, developed by the Jenner Institute at the University of Oxford, has the potential to help rapidly close the gap between supply and demand for an effective anti-malarial vaccine. The supply of RTS,S/AS01 is approximately 18 million doses by the end of 2025, and demand for the vaccine exceeds supply.

Wirth noted that R21/Matrix-M’s manufacturer – the Serum Institute of India – aims to deliver more than 100 million doses per year, meaning the new vaccine could expand access and “have a significant impact on public health.”

The approval of the new vaccine has been welcomed by those fighting malaria globally, who hope it will intensify efforts to expand access to a safe and effective malaria vaccine as part of a multi-pronged strategy to control and eradicate the disease by 2030. .

David Marlow, CEO of Gavi, said: “The SAGE-MPAG joint recommendation of the R21/Matrix-M vaccine to the World Health Organization represents another step towards our goal of creating a malaria-free life for every child. A big step forward.”

“This vaccine, along with the existing RTS,S/AS01 vaccine, will be an effective complement to existing malaria interventions. Once prequalified by WHO, it will play a key role in meeting high demand in endemic countries.”

Slow progress

The news comes as efforts to control and eradicate malaria have stalled or reversed in parts of Africa. Climate change is allowing the Anopheles mosquito, which transmits the malaria parasite, to expand its range into new areas.

At the same time, efforts to control mosquito populations are hampered by an increase in the frequency and severity of extreme weather events. Growing resistance to the most widely used pesticides and drugs is also beginning to undermine the impact of key measures to prevent and treat the disease.

Slow progress against malaria has prompted African heads of state to use September’s United Nations General Assembly to call for urgent action and increased funding to get back on track to eliminate the disease from the continent. Of the approximately 247 million malaria cases and 619,000 malaria deaths recorded in 2021, the vast majority (95%) occurred in sub-Saharan Africa, with the majority of deaths occurring in children under 5 years of age.

Before making the decision, the WHO’s joint SAGE-MPAG group considered evidence, including results from a newly published Phase 3 randomized controlled trial, which showed the vaccine is safe and provides protection against clinical malaria in African children. High level of protection.

How vaccines work

Both the RTS.S/AS01e and new R21/Matrix-M vaccines work by tagging the malaria parasite into the body’s immune system early in its life cycle, before it has a chance to multiply.

By packaging proteins from the malaria parasite with proteins from the hepatitis B virus that typically trigger a strong immune response, the vaccine can train the immune system to target the parasite when it is most vulnerable, immediately after it enters the host. ) to attack. New host.

The Matrix-M component of the R21 vaccine also acts as a potent adjuvant, helping the immune system mount a stronger, longer-lasting response to the parasite.

While welcoming the decision to approve the vaccine, Dr Michael Charles, chief executive of the Roll Back Malaria Partnership, also issued a warning. “There is no magic bullet for eradicating malaria,” Dr. Charles noted. “There are still significant obstacles to overcome,” he said, including severe funding shortfalls.

But on a day when the Nobel Prize in Physiology and Medicine was awarded to researchers who developed an mRNA vaccine against COVID-19, the WHO director-general was optimistic that a malaria vaccine could be similarly transformative. “I had a dream that one day we would have a safe and effective vaccine (against malaria),” he recalls. “Now we have two.”