Ahead of clinical trials , a new type of vaccine offers hope to malaria researchers

gentle stir has emerged this year in the vexed world of malaria research , where decades of breakthroughs have brought hope and frustration in equal measure .

A promising new blueprint for a vaccine with properties approximating those developed for COVID-19 is the latest cause of optimism in the fight against a disease that infects hundreds of millions each year and kills hundreds of thousands .

American scientists recently tried a new approach using a novel RNA-based platform similar to the one deployed in the development of some COVID-19 vaccines .

Their design circumvents a protein contained in the malaria parasite , Plasmodium , that impairs the ability of T-cells in the immune system to trigger an effective immune response , and so renders vaccines ineffective .

The proposed self-amplifying mRNA vaccine , patented in February by Dr Richard Bucala of Yale University and Dr Andy Geall with Precision NanoSystems , allows the body to produce the needed T-cells to completely immunise against malaria . The vaccine is reportedly effective at much lower doses because it can rapidly produce copies of itself inside the cell .

While the vaccine has yet to be tested on humans and there are no published data , Dr Bucala states that it has provided a high level of protection in tests on mice .

The problem malaria poses for scientists is that it comes from its pathogen in the form of a parasite , which is “ 100 times more complex than the most complex bacteria ,” according to Dr Laurent Rénia , executive director of A * STAR ’ s infectious disease labs and principal investigator at the Singapore science and technology research agency .

Whereas a bacteria or virus may have up to 300 genes coding proteins , there are some 5,000 in the malaria parasite , which in turn goes through multiple stages of development and is constantly developing throughout its life cycle .

Scientists are still getting to know more about the proteins on the pathogen ’ s surface , but they still don ’ t know the function of at least 50 percent of the genomes of the parasite since it uses multiple ways to infect human cells so that even when one means is found to block it , it will find another , effective way to achieve its goal .

“ When you try to develop a vaccine which will block the lock and key mechanism that allows the pathogen to go in , it will use another key and another lock . And we don ’ t know all of these up to now — we know some , but not all of them ,” Dr Rénia told Global Health Asia-Pacific .

The newly patented vaccine is now at the Oxford University institution that facilitated the AstraZeneca COVID-19 vaccine , as it is one of the few places in the world that is doing phase 1 studies in malaria . Researchers there are infecting human volunteers with the disease after immunising them .

Without published data , though , it ’ s impossible to tell if the proposed vaccine will be a cause for joy or another worthy but ineffective effort to counter the world ’ s most deadly infection .

“ Yes , it ’ s an interesting target , but let ’ s now wait for evidence that mRNA will work . The hype around this platform for COVID-19 might just be giving it a lot of publicity ,” Dr Rénia added .

22 JUNE 2021 GlobalHealthAsiaPacific . com