Malaria vaccine data ‘best yet’

[OUAGADOUGOU] Researchers say they plan to launch a new malaria vaccine next year after tests on children in West Africa showed it was 80 percent effective.

More than 100 malaria vaccine candidates have been tested in humans over the past few decades, but none have previously met the World Health Organization’s efficacy target of over 75 percent.

Scientists have warned that progress in the fight against the mosquito-borne disease, which claimed over 640,000 deaths in 2020, most of them children in sub-Saharan Africa, has stalled.

“This is another first in the history of malaria vaccine research.”

Halidou Tinto, Regional Director, Health Sciences Research Institute, Burkina Faso

Researchers at Oxford University and the Health Sciences Research Institute (IRSS) in Nanoro, Burkina Faso, say a booster shot of the malaria vaccine candidate, called R21, showed 80 percent efficacy in children who received the highest dose a year after an initial three – Cans course.

The 78% efficacy was maintained for two years after the booster was administered during the study involving 450 children between the ages of five and 17 months at Nanoro’s Clinical Research Unit. There were no serious side effects, the researchers say.

This was announced by IRSS regional director Halidou Tinto, professor of parasitology and principal investigator of the study SciDev.Net: “This is another first in the history of malaria vaccine research.

“This means we can maintain greater than 75 percent efficacy with a booster shot over the long term, which should give children in malaria-endemic areas like Burkina very good protection from malaria as they age, when they are most vulnerable.”

The vaccine – which Tinto describes as an improved version of the RTS,S vaccine being rolled out in a number of African countries – had shown 77 percent efficacy in the first year in a previous study in 2021.

The Phase 2 study was extended for an additional two years to assess whether additional booster doses are required to maintain this high level of efficacy over a longer period of time.

Tinto says he’s “optimistic” that the latest findings can also be replicated in an ongoing Phase 3 study involving 4,800 children in Burkina Faso, Mali, Kenya and Tanzania. Results are expected later this year.

Launch 2023

The R21 vaccine, developed at Oxford University’s Jenner Institute, is approved for manufacture by the Serum Institute of India (SII).

“We are already planning in collaboration with our partners … programmatic use of R21 starting in 2023 in a population of at least 250,000 children in Burkina Faso to accelerate the agenda for large-scale use of this vaccine in Africa,” Tinto said.

He said SII has committed to producing at least 100 to 200 million doses of the R21 vaccine per year, subject to WHO recommendation for its use. “This will complement the only vaccine currently recommended by the WHO (RTS,S), whose current production capacity cannot meet global demand,” Tinto added.

RTS,S, the world’s first malaria vaccine, was recommended by WHO in October 2021 for use in at-risk children in sub-Saharan Africa and other regions with moderate to high malaria transmission Plasmodium falciparum Parasite.

However, scientists have stressed the need for further vaccine development and research investment.

Adrian Hill, director of the Jenner Institute, co-author of the R21 study published in Lancet infectious diseasessaid this is “the best data yet” on a malaria vaccine.

“We are pleased to note that a standard four-dose immunization regimen can now, for the first time, achieve the high level of efficacy over a two-year period that has been an aspired goal for malaria vaccines for so many years,” he said.

He said the vaccine would offer “lasting protection” to the most important group that needs it: young African children. However, he stressed that the vaccine’s 77 percent accuracy was dependent on other control measures such as insecticides and bed nets, which should continue to be used.

James Tibenderana, who will take over as CEO of the non-profit Malaria Consortium in October, called the results “remarkable”.

Tibenderana, who was not involved in the R21 trials, said the rapid development and rollout of COVID-19 vaccines has shown that it is possible to shorten the timeframe for vaccine development and distribution while mitigating risks.

“I hope these results will motivate increased and sustained investment in malaria vaccine research and development and equitable access as they prevent malaria infections and save lives,” he said.

This piece was produced by SciDev.Net’s Global Desk.