The vaccine candidate PfSPZ, developed by US biotech company Sanaria, concentrates the known immunising effect of exposure to irradiated mosquitoes.
High doses of the vaccine protected 80% of experimental subjects (12 out of 15) from infection with malaria.
The vaccine relies on injecting live but weakened malaria-causing parasites into the patient’s bloodstream.
It has been known for decades that irradiating mosquitoes causes them to confer a slight immunity against malaria on humans they bite.
The new vaccine concentrates this effect by extracting the weakened protozoans from the mosquitoes and collecting them in vials.
The Phase 1 clinical trial used 57 volunteers with no history of malaria, giving different doses of the vaccine to 40 of them; all 57 were then exposed to infected mosquitoes.
Of the 15 given high doses of the vaccine, only three contracted malaria; almost all of the other 42 subjects contracted the disease.
The level of health risk incurred by these volunteers is itself notable.
Lead study author Dr Robert Seder of the Vaccine Research Center at the National Institutes of Health, 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.
“The next critical questions will be whether the vaccine is durable over a long period of time and can the vaccine protect against other strains of malaria.”
The WHO estimates that 219 million people were suffering from malaria in 2010, with 660,000 fatalities.