A malaria vaccine that uses a weakened form of the parasite has passed a “critical milestone” in human safety trials, say researchers.
Doctors used a genetically modified form of malaria that was unable to cause a full infection in people.
Trials, published in the journal Science Translational Medicine, suggested it was safe and generated a good immune response.
Tropical disease experts described the findings as “promising”.
The malaria parasite goes through multiple stages both in mosquitoes and inside the human body.
The team at the Centre for Infectious Disease Research, in Seattle, deleted three genes from the parasite so it could not infect liver cells.
The idea is that “infecting” people with the weakened parasite will expose the immune system to malaria, but the parasite will not be able to complete its lifecycle to cause disease.
Ten people took part in the safety trials. No-one went on to develop the disease and there were …