Vaccine results raise hopes of mass deployment

The Oxford R21/Matrix-M vaccine maintains a high level of protection of around 70-80% after a single booster dose.

A booster dose of a new malaria vaccine maintains a high level of protection against the disease, researchers assured Thursday (8). Developed by Oxford University scientists, this vaccine could represent a game-changer in the fight against the disease, an international research team 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. It is the first time that a vaccine has exceeded the 75% efficacy target set by the WHO.

We could see a very significant reduction in this horrific burden of malaria, reduction in death and disease, in the coming years, certainly by 2030.”

Adrian Hill, Oxford vaccine specialist and co-author of the study

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. For the group that received the highest dose of the adjuvant, the vaccine’s effectiveness increased to 80%, according to the results of a phase 2 study published on Thursday. 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.

A target of 200 million doses per year

“It’s fantastic to see such high potency after a single booster dose”, said one of the study’s authors, Halidou Tinto, from the Health Research Institute of Burkina Faso IRSS. Halidou Tinto, who was involved in testing the two malaria vaccines, said GSK’s vaccine had an optimal efficacy of about 60%. “So I can confirm that R21 (The Oxford Vaccine: Editor’s Note) is much more effective”he said at a press conference. “We could see a very substantial reduction in this horrific burden of malaria, a reduction in deaths and disease, in the coming years, certainly by 2030.”, said Adrian Hill, a vaccine specialist in Oxford and co-author of the study. According to him, a 70% 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 “Wants to and able to produce 200 million cans per year from next year”said Adrian Hill. The six to ten million doses that GSK can produce per year are not “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.

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