Could a Breakthrough Malaria Vaccine Finally Be on the Horizon?

A malaria vaccine could finally become a reality thanks to breakthrough technology, researchers said in a new study. 

Scientists from New Zealand and Australia have developed an mRNA vaccine, similar to the type of vaccine developed for COVID-19, that could effectively stimulate an immune cell response against the malaria-causing parasite in preclinical trials. 

The research group has been working toward a malaria vaccine for years, but was initially focused on developing a different type of vaccine. However, since turning their attention to possibilities with mRNA vaccines they seem to be making greater strides.

Malaria is a parasitic disease spread through mosquito bites. Though typically not feared in the United States, a cluster of domestic borne cases have been detected in Florida this summer. This has left officials concerned that mosquitos in the U.S. are now carrying the disease.

Those who contract malaria typically experience a fever, headache and chills. Whilethere are medications available to fight the disease, the disease can be deadly, especially to children under the age of 5, if left untreated.

The World Health Organization estimates 247 million cases of malaria and 619,000 deaths globally in 2021. More than half of these cases occurred in just four African countries — Nigeria, Democratic Republic of Congo, Tanzania and Niger.

Prior to the COVID-19 pandemic, the Centers for Disease Control and Prevention identified around 2,000 cases of malaria each year in the U.S. — typically brought in by travelers. Of those, around 300 cases resulted in severe illness, and 5 to 10 people with malaria died each year.

A malaria vaccine called RTS,S is available, but only given to children who live in high risk areas. The vaccine shows modest efficacy, and does not prevent transmission, meaning people can still unknowingly spread it. 

It’s because of this that researchers are fervently working to find a more universal solution.

Unlike other mRNA vaccines, including the COVID-19 vaccine, which works by neutralizing antibodies, this new vaccine takes a different approach — targeting malaria right where it starts, in the liver, researchers explained. 

After initial exposure, say, through a mosquito bite, the parasite uses the bloodstream to travel to the liver where the parasite matures, before going on to infect blood cells, which is when an infected person will start to show symptoms. 

“Our unique approach relies on T-cells which play a critical role in immunity,” Mitch Ganley, co-author of the study, said in a statement. “Specifically, a type of T-cell called a tissue-resident memory T-cell, that halts malaria infection in the liver to completely stop the spread of infection.”

T-cells are a type of white blood cell and are essential for helping the body protect itself from infection. T-cells play a critical role in the ongoing study of many conditions and viruses, from HIV to cancer.

Researchers also note that a key difference with this vaccine is that it works even if a person has been previously exposed to the disease.

“A lot of malaria vaccines undergoing trials have worked really well in animal models or when they’re given to people who haven’t had malaria before, but they don’t work well when given to people living in malaria-endemic regions,” Lauren Holz, Ph.D., researcher at the University of Melbourne and co-author of the paper said in a statement. “In contrast, our vaccine is still capable of generating protective liver-specific immune cells and providing protection even when the animal models have been pre-exposed to the disease.”

Vaccines against parasitic diseases do not yet exist, so if this one proves to be effective, it could signal a momentous step forward for vaccine development as a whole.

As next steps, the research team will seek to begin clinical trials in humans, which could take several years.