CD8A and malaria: In its first generation, prime-and-trap was based on skin priming using plasmid DNA encoding the P. yoelii (Py) rodent malaria CSP antigen followed by a single intravenous (IV) dose of cryopreserved radiation attenuated spz (cryo-RAS) to direct and “trap” the activated and expanded CD8+ T cells in the liver.