Thursday, August 15, 2013

Malaria vaccine shows promise

Charlene Porter in U.S. government health researchers report some success in early human testing of a malaria vaccine. In a trial involving fewer than 60 patients, the vaccine cleared three important hurdles: it's safe for humans; it produces an immune response; and it offered malaria protection in adults.

Sanaria Inc., a biotechnology firm in Maryland, developed the vaccine in pursuit of its corporate mission devoted to cracking this scientific puzzle. The National Institute of Allergy and Infectious Diseases (NIAID), with collaborators from the Walter Reed Army Institute of Research and the Naval Medical Research Center, evaluated the Sanaria product at the National Institutes of Health (NIH) near Washington.

Fifty-seven healthy adults consented to be in what is called a Phase 1 trial. Among the volunteers, 40 participants received the vaccine and 17 did not. Making sure a vaccine is safe is one of the key objectives in a trial at this stage, so after the volunteers were vaccinated intravenously, the researchers let a week pass to see if adverse reactions emerged, or if any signs of malaria were induced by the vaccine.

The trial vaccine is known as PfSPZ, after Plasmodium falciparum, the most deadly of the malaria-causing parasites. PfSPZ is made from live but weakened sporozoites, the offspring of the infective malaria spores.

The NIAID volunteer patients showed no signs of the disease itself over that first week, and developed varying levels of antibodies against malaria, depending on the level of the PfSPZ dose they received….

Malaria is transmitted to people and animals by mozzies. Malarial sporozoites develop inside oocysts and are released in large numbers into the hemocoel of Anopheles stephensi mosquitoes. This false-colored electron micrograph shows a sporozoite migrating through the cytoplasm of midgut epithelia. Image by Ute Frevert; false color by Margaret Shear. Wikimedia Commons, under the Creative Commons Attribution 2.5 Generic license

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