Scientists identify potential vaccine candidate for malaria

U.S. researchers have identified an antigen that generates antibodies to hinder the ability of malaria parasites to multiply, an advancement that could lead to the development of a malaria vaccine.

The discovery of the antigen, known as PfSEA-1, is a critical addition to the limited pool of antigens currently used in candidate malaria vaccines, the researchers reported Thursday in the U.S. journal Science.

An estimated 627,000 people die from malaria each year according to the World Health Organization, with most deaths from the mosquito-borne parasitic disease occurring among young children living in sub-Saharan Africa.

People who live in areas where malaria is common frequently develop protective immune system responses that can limit malaria parasite levels in the blood and prevent the high fever and illness associated with malaria infection.

Using plasma samples from 2-year-old Tanzanian children who were either resistant or susceptible to malaria infection, researchers performed gene-screening experiments and a series of laboratory tests that identified PfSEA-1.

Multiple tests confirmed that antibodies to PfSEA-1 halted malaria infection at the point when the parasite leaves one red blood cell to invade a new one, which may protect against severe malaria infection.

"Many researchers are trying to find ways to develop a malaria vaccine by preventing the parasite from entering the red blood cell, and here we found a way to block it from leaving the cell once it has entered," said Jonathan Kurtis, director of the Center for International Health Research at Rhode Island Hospital, and the study's principal investigator. "If it's trapped in the red blood cell, it can't go anywhere .. it can't do any further damage. "