The anti-CD19/CD22 Bispecific CAR lentiviruses are replication incompetent, HIV-based, VSV-G-pseudotyped lentiviral particles that are ready to infect almost all types of mammalian cells, including primary and non-dividing cells. These viruses transduce the ScFv (single-chain variable fragments) of anti-CD19 (clone FMC63) and anti-CD22 (clone m971) linked to a 2^nd generation CAR (Chimeric Antigen Receptor) containing CD8 hinge and transmembrane domains, and the 4-1BB and CD3ζ signaling domains.