Immunization with attenuated Plasmodium sporozoites can provide high levels of protection in mice, non-human primates, and humans.9, 10, 11, 12 Protection is mediated by CD8+ T cells, which target a set of mostly unknown pre-erythrocytic stage antigens.13, 14, 15, 16, 17, 18 Activated CD8+ T cells can kill infected hepatocytes, thereby preventing blood-stage infection, which is responsible for the clinical symptoms of the disease. Here, CD8A is linked to infection.