April 23 (UPI) -- A new malaria vaccine developed by researchers at the University of Oxford provides 77% protection against the mosquito-borne parasite for one year, a study published online Friday by the Lancet found.
The vaccine, called R21/Matrix-M was tested at two dosing levels in 450 people ages 5 to 17 months in Burkina Faso, an African nation where the parasite is common, the researchers said.
In preliminary findings that have not yet been peer-reviewed, the high-dose shot offered 77% protection against the parasite, while the low-dose one gave 71% protection, both over 12 months of follow-up, with no serious side effects, they said.
If confirmed in future clinical trials, the vaccine would be the first to meet the World Health Organization's minimum threshold for malaria vaccine effectiveness of 75%, according to the researchers.
"These new results support our high expectations for the potential of this vaccine, which we believe is the first to reach the WHO's goal of a vaccine for malaria with at least 75% efficacy," study co-author Adrian Hill said in a press release.
"With the commitment by our commercial partner, the Serum Institute of India, to manufacture at least 200 million doses annually in the coming years, the vaccine has the potential to have major public health impact," said Hill, a professor of vaccinology at the University of Oxford in England.
Malaria is a life-threatening illness caused by parasites transmitted to people through mosquito bites, and it is among the leading causes of death among children in Africa, according to the WHO.
Although preventable and curable, there were nearly 230 million cases worldwide and 409,000 deaths in 2019, including more than 270,000 children, the agency estimates.
Previous attempts in developing an effective malaria vaccine to date have only achieved 55% efficacy in trials with African children, the WHO said.
A malaria vaccine has proved challenging because there are thousands of genes in the parasite compared to around a dozen in the coronavirus and a high immune response is needed to fight off the disease, according to Hill.
Still, the new malaria shot provided some of the framework used by Oxford research, with pharmaceutical giant AstraZeneca, to develop their COVID-19 vaccine, he said.
For this Phase 2 clinical trial, which began in 2019, Hill and his colleagues in Africa tested the malaria vaccine in 450 infants in the region of Nanoro, Burkina Faso.
Participants were split into three groups, with the first two groups receiving the R21/Matrix-M at either a low dose or high dose and the third being given a rabies vaccine to serve as the control group, the researchers said.
Vaccines were administered from early May to early August 2019, just prior to the peak malaria season in the region, they said.
Based on the positive findings in this trial, participant recruitment for a Phase 3 trial, the final stage in the research and development process, has already begun, with plans to include 4,800 children ages 5 to 36 months across four African countries, according to the researchers.
"These are very exciting results showing unprecedented efficacy levels from a vaccine that has been well tolerated in our trial program," study co-author Halidou Tinto said in a statement.
"We look forward to the upcoming Phase 3 trial to demonstrate large-scale safety and efficacy data for a vaccine that is greatly needed in this region," said Tinto, a professor in parasitology at the Research Institute for Health Sciences in Burkina Faso.