Background: Currently licensed and approved malaria subunit vaccines provide modest, short-lived protection against malaria. Immunization with live-attenuated malaria parasites is an alternative vaccination strategy that has potential to improve protection.
Methods: We conducted a double-blind, controlled clinical trial to evaluate the safety, side-effect profile, and efficacy of immunization, by means of mosquito bites, with a second-generation genetically attenuated parasite (GA2) - a single knockout NF54 parasite (sporozoite form) with extended development into the liver stage.