A team of scientists in the US has developed a novel vaccine based on mRNA technology that protects against malaria in animal models.
The vaccine relies on the circumsporozoite protein of the Plasmodium falciparum — the parasite species which causes the vast majority of malaria deaths globally — to elicit an immune response.
However, rather than administering a version of the protein directly, this approach uses mRNA — accompanied by a lipid nanoparticle that protects from premature degradation and helps stimulate the immune system — to prompt cells to code for circumsporozoite protein themselves.
Those proteins then trigger a protective response against malaria but cannot actually cause infection.
“Recent successes with vaccines against Covid-19 highlight the advantages of mRNA-based platforms — notably highly targeted design, flexible and rapid manufacturing and ability to promote strong immune responses in a manner not yet explored,” said Dr. Evelina Angov, a researcher at Walter Reed Army Institute of Research Malaria Biologics Branch.
“Our goal is to translate those advances to a safe, effective vaccine against malaria,”Angov added. The findings are published in the journal npj Vaccines.
A safe, effective malaria vaccine has long been an elusive target for scientists. The most advanced malaria vaccine is RTS, S. RTS, S is based on the circumsporozoite protein of P. falciparum, the most dangerous and widespread species of the malaria parasite.
While RTS, S is an impactful countermeasure in the fight against malaria, field studies have revealed limited sterile efficacy and duration of protection. The limitations associated with RTS, S, and other first-generation malaria vaccines have led scientists to evaluate new platforms and second-generation approaches for malaria vaccines.
“Our vaccine achieved high levels of protection against malaria infection in mice,” said Katherine Mallory, a WRAIR researcher. “While more work remains before clinical testing, these results are an encouraging sign that an effective, mRNA-based malaria vaccine is achievable.”
