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Malaria vaccine shows early promise in clinical trials

A malaria vaccine has shown promising results in early stage clinical trials, according to researchers. Researchers found the vaccine, which is being developed in the US, protected 12 out of 15 patients from the disease, when given in high doses.

The method is unusual because it involves injecting live but weakened malaria-causing parasites directly into patients to trigger immunity. The research is published in the journal Science.

Lead author Dr Robert Seder, from the Vaccine Research Center at the National Institutes of Health, in Maryland, said: "We were excited and thrilled by the result, but it is important that we repeat it, extend it and do it in larger numbers."

Many bites
It has been known for several decades that exposure to mosquitoes treated with radiation can protect against malaria. However, studies have shown that it takes more than 1,000 bites from the insects over time to build up a high level of immunity, making it an impractical method of widespread protection. Instead, a US biotech company called Sanaria has taken lab-grown mosquitoes, irradiated them and then extracted the malaria-causing parasite (Plasmodium falciparum), all under sterile conditions.


“They are clearly very early stage trials in small numbers of volunteers, but without question we are extremely encouraged by the results!” said Dr Ashley Birkett Path Malaria Vaccine Initiative. These living but weakened parasites are then counted and placed in vials, where they can then be injected directly into a patient's bloodstream. This vaccine candidate is called PfSPZ. Read more