New Malaria Vaccine Candidate Developed From Algae

Researchers have developed a new candidate for malaria vaccine with the help of algae-produced malaria parasite protein.

Paired with an immune-boosting cocktail suitable for use in humans, the algae-produced protein generated antibodies in mice that nearly eliminated mosquito infection by the malaria parasite.

Besides its effectiveness as a protein producer, algae is an advantageous tool for developing vaccines because it is cheap, easy and environmentally friendly.

"Most malaria vaccine approaches are aimed at preventing humans from becoming infected when bitten by mosquitoes that carry the parasite," said senior author of the study Joseph Vinetz, professor of medicine at the University of California (UC), San Diego School of Medicine.

"Our approach is to prevent transmission of the malaria parasite from infected humans to mosquitoes," Vinetz explained.

The researchers turned to an algae to produce Pfs25, a protein found on the surface of the malaria parasite's reproductive cells. They believed that Pfs25 might block transmission of the parasite to the next host.

They introduced the Pfs25 gene into the algae by shooting the DNA into the plant cell's nucleus.

Then, after they let the algae do the work of replicating, building and folding the protein, the team was able to purify enough functional Pfs25 for laboratory testing.

In experiments, the researchers found that only one of 24 mosquitoes (4.2 percent) that consumed the Pfs25/adjuvant-treated mouse serum was positive for the malaria parasite.

That is compared to the 28 infected mosquitoes out of the 40 in the control group (70 percent).

Adjuvants are molecules that help stimulate the immune system's response to Pfs25.

"We are really excited to see that Pfs25 produced by algae can effectively prevent malaria parasites from developing within the mosquito," study co-author Stephen Mayfield from UC San Diego.

The study was published in the journal Infection and Immunity.