The study involved about 200 hungry mosquitos biting a human subject's arm. Human participants placed their arms directly over a small box full of the bloodsuckers.

"We use the mosquitoes like they're 1,000 small flying syringes," said researcher Dr. Sean Murphy, as reported by NPR.

Three to five "vaccinations" took place over 30-day intervals.

The mosquitos gave minor versions of malaria that didn't make people sick, but gave them antibodies. Efficacy from the antibodies lasted a few months.