For example, post chimeric antigen receptor (CAR) T-cell therapy, patients are at risk of infection during the post-transplant period as a consequence of prolonged cytopenia following depletion of normal CD19-expressing B-cells.25 CAR T-cell therapy may result in profound immune deficits that may persist for several years, warranting antiviral (acyclovir or valacyclovir) prophylaxis concomitant with subsequent lines of therapy. Here, CD19 is linked to infection.