Chimeric antigen receptors (CAR) T cells are a specialized therapy used as a cancer treatment in which a patient's immune cells are engineered to better identify and kill cancer cells. CAR T cell therapy can be effective for some types of leukemias and lymphomas but they also have the capacity to damage healthy calls, including B cells, the immune cells responsible for secreting antibodies. Many vaccines work by inducing your body to produce antibodies in response to a specific stimulus against which the vaccine is targeted. Therefore, studying how to maintain vaccine efficacy following CAR T cell therapy is an important research focus.