A vaccine for malaria has just passed its first clinical trial with human volunteers, giving them 100 percent immunity to the parasite that causes the disease.
Malaria kills hundreds of thousands of people worldwide each year, and is passed on by a parasite spread by mosquitos.
Researchers from the University of Tübingen in southern Germany, are working with tech company Sanaria to develop a 100 percent effective vaccine.
Unlike other vaccines, this one uses living malaria parasites, but combines them with an antimalarial drug called chloroquine.
The living pathogens prompt a strong immune system response, but then the chloroquine kills them as they enter the bloodstream, preventing any illness.
The company said early results were a positive sign, and the researchers will be moving on to larger clinical trials.