Genetically-engineered parasite could serve as malaria vaccine

Malaria parasites weakened through precise gene deletions could be used as a vaccine to protect against malaria infection, according to a study recently published in Vaccine.

The study followed up on previous research that tested a new malaria vaccine with parasites weakened by radiation. The trial was promising but vaccination required intravenous administration with multiple high doses. Researchers at Seattle BioMed outlined a method to attenuate the malaria parasite through genetic engineering, which could offer a consistently protective malaria vaccine.

"Malaria is one of the world's biggest killers, and threatens 40 percent of the world's population, yet still no effective vaccine exists," Stefan Kappe, the lead author of the paper, said. "In this paper we show that genetically engineered parasites are a promising, viable option for developing a malaria vaccine, and we are currently engineering the next generation of attenuated parasite strains with the aim to enter clinical studies soon."

The research marked the first time scientists were able to create a weakened version of the malaria parasite by altering its DNA. The researchers tested the safety of the modified parasite by injecting six human volunteers through mosquito bites. Five of the six volunteers showed no infection with the parasite, suggesting the new technique could lead to a malaria vaccine.

"Our approach offers a new path to make a protective malaria vaccine that might overcome the limitations of previous development attempts," Kappe said. "Genetically engineered parasites potentially provide us with a potent, scalable approach to malaria vaccination. Our results are very encouraging, providing a strong rationale for the further development of live-attenuated strains using genetic engineering."

According to the World Health Organization, there were 219 million reported cases of malaria in 2010, causing up to 1.2 million deaths throughout the world. There is no effective vaccine against the disease.