New vaccine based on mRNA technology protects against malaria in animal models

Scientists from the Walter Reed Army Institute of Research and the Naval Medical Research Center have teamed up with researchers at the University of Pennsylvania and Acuitas Therapeutics to develop a new vaccine based on mRNA technology that protects against malaria in animal models, publishing their results in Npj vaccines.

In 2019, there were approximately 229 million cases of malaria and 409,000 deaths worldwide, creating an extraordinary cost in terms of human morbidity, mortality, economic burden and regional social stability. Globally, Plasmodium falciparum is the parasitic species that causes the vast majority of deaths. Those most at risk of serious illness are pregnant women, children, and malaria-naive travelers. The development of countermeasures against malaria has always been a priority area of ​​research for the Department of Defense, as the disease remains a major threat to US military forces deployed in endemic regions.

A safe and effective malaria vaccine has long been an elusive target for scientists. The most advanced malaria vaccine is RTS, S, a first generation product developed in partnership with WRAIR. RTS, S is based on the circumsporozoite protein of P. falciparum, the most dangerous and widespread species of malaria parasite. While RTS, S is an effective countermeasure in the fight against malaria, field studies have shown sterile efficacy and limited duration of protection. Limitations associated with RTS, S and other first generation malaria vaccines have led scientists to evaluate new second generation platforms and approaches for malaria vaccines.

Recent successes in COVID-19 vaccines highlight the benefits of mRNA-based platforms, including highly targeted design, flexible and rapid manufacturing, and the ability to promote strong immune responses in a way that has not yet been explored. Our goal is to translate these advances into a safe and effective vaccine against malaria. “

Dr Evelina Angov, Malaria Biologics Branch researcher at WRAIR and lead author of the article

Like RTS, S, the vaccine relies on the circumsporozoite protein of P. falciparum to trigger an immune response. However, rather than directly delivering a version of the protein, this approach uses mRNA – along with a lipid nanoparticle that protects against premature degradation and helps boost the immune system – to trick cells into coding for them. even the circumsporozoite protein. These proteins then trigger a protective response against malaria but cannot actually cause infection.

“Our vaccine has achieved high levels of protection against malaria infection in mice,” said Katherine Mallory, WRAIR researcher at the time of article submission and lead author of the article. “Although there is still work to be done before clinical trials, these results are an encouraging sign that an effective mRNA-based malaria vaccine is feasible.”

The research was conducted according to an approved protocol for the use of animals at a facility accredited by AAALAC International, in accordance with the Animal Care Act and other federal laws and regulations relating to animals and experiments involving and adheres to the principles set out in the Guide to the Care and Use of Animals. Laboratory Animals, NRC Publication, 2011 Edition.