Vaccine gives kids in Mali strong malaria protection: study

(Jaimie Duplass)

A malaria vaccine tested by US and African researchers in Mali produced a robust immune response in young children, the group most vulnerable to the mosquito-borne disease, a report released Thursday showed.

The vaccine, based on a single strain of the falciparum malaria parasite - the most common and deadliest form of the parasite found in Africa - was tested on 100 children between the ages of one and six in a rural part of the west African country of Mali.

The children were given one of three, progressively stronger doses of the vaccine or a control vaccine against rabies.

All three doses of the malaria vaccine were well tolerated by the children and produced "very strong antibody responses that were sustained for at least a year," said the report which was published online Thursday in PLoS ONE, the journal of the Public Library of Science.

In fact, the report said, the antibody levels the vaccine produced in the children were as high or higher than antibody levels found in adults, who have developed immune responses to the parasite over lifelong exposure to malaria.

"These findings imply that we may have achieved our goal of using a vaccine to reproduce the natural protective immunity that normally takes years of intense exposure to malaria to develop," said Christopher Plowe, professor and chief of the malaria section at the Center for Vaccine Development at the University of Maryland's school of medicine, and a lead author of the study.

"I hope this study leads to a lifesaving vaccine for the children of Africa," said E. Albert Reece, dean of the school of medicine.

Although deaths from malaria have been halted in places like North America and Europe, the mosquito-borne disease still claims the lives of nearly one million people a year, mostly in Africa and most of them children under the age of five.

The vaccine tested in Mali targets malaria when the parasite transmitted to the human by a mosquito multiplies in the blood, leading to disease and, if left untreated, often painful death.

Other blood-stage vaccines have been tested but none has shown the ability to prevent malaria, the report in PLoS ONE says.

University of Maryland researchers collaborated with a group of Malian researchers from the Malaria Research and Training Center, led by Mahamadou Thera and Ogobara Doumbo for the study.

Based on the success of the vaccine on the small sample of children, the researchers are conducting a broader trial on 400 Malian children.

That study will also examine whether the single-strain vaccine can protect against the broad array of malaria parasites that exist.

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