Les résultats d’un vaccin contre le paludisme suscitent l’espoir d’un déploiement massif

Malaria vaccine results raise hopes for mass adoption

A cheap vaccine could be produced on a large scale in a few years. Developed by Oxford University scientists, it could represent a game changer in the fight against the disease, an international team of researchers recently said in the journal Lancet Infectious Diseases. Malaria, a mosquito-borne parasitic disease, killed 627,000 people in 2020 alone – mostly African children.

Last year, another vaccine from British pharmaceutical giant GSK became the first malaria vaccine to be recommended for widespread use by the World Health Organization (WHO). Since then it has been passed on to more than a million children in Africa. However, research has shown that the effectiveness of GSK’s vaccine is around 60% and decreases dramatically over time, even with a booster dose.

According to a study published last year, Oxford’s R21/Matrix-M vaccine was 77% effective in preventing malaria. This is the first time a vaccine has exceeded the 75% efficacy target set by the WHO.

“Much more efficient”

For the study, 450 children aged five to 17 months in Burkina Faso — where malaria accounts for around 22% of all deaths — received three doses in 2019. They were divided into three groups: two received different doses of Matrix-M adjuvant, a vaccine ingredient patented by Novavax that is also used in the American biotechnology company’s Covid vaccine; the third control group received a rabies vaccine. Ahead of the 2020 rainy season (when malaria cases increase), 409 children returned for a booster shot.

In the group that received the highest dose of the adjuvant, vaccine efficacy increased to 80%, according to results of a phase 2 study published in early September. At the lowest dose, efficacy was 70%.

Importantly, one month after receiving the booster shot, antimalarial antibodies returned to levels similar to those after the first dose received a year earlier, the study found.

“It’s fantastic to see such high efficacy after a single booster dose,” said one of the study’s authors, Halidou Tinto, of the Burkina Faso Health Research Institute, IRSS. Mr Tinto, who was involved in testing both malaria vaccines, said GSK’s vaccine had an optimal efficacy of around 60%. “I can therefore confirm that R21 (the Oxford vaccine) is much more effective,” he told a news conference.

“By 2030”

“We could see a very significant reduction in this horrific burden of malaria, a reduction in deaths and disease, in the coming years, certainly by 2030,” hopes Adrian Hill, a vaccines specialist at Oxford and co-author of the study. According to him, a 70 percent reduction in malaria deaths could be achieved within that timeframe, thanks in part to the large number of vaccine doses that could be manufactured quickly.

Oxford has partnered with the world’s largest vaccine manufacturer, the Serum Institute of India. The institute “targets and has the ability to manufacture 200 million doses per year by next year,” Hill said. The six to 10 million doses that GSK can produce per year are “not enough for 40 million children who need four doses in the first year,” he said. And the Oxford vaccine would likely cost a few dollars a dose, less than half the $9 for GSK’s version, he added.

Results from a phase 3 trial involving 4,800 participants in four countries are expected later this year and could potentially lead to approval of the vaccine.

Daniel LAWLER/AFP

A cheap vaccine could be produced on a large scale in a few years. Developed by Oxford University scientists, it could represent a game changer in the fight against the disease, an international team of researchers recently said in the journal Lancet Infectious Diseases. Malaria, a mosquito-borne parasitic disease, has…


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