Ram R, Hagin D, Kikozashvilli N, et al. Safety and Immunogenicity of BNT162b2 mRNA COVID-19 Vaccine in Patients After Allogeneic HCT or CD19-based CART Therapy: Single-Center Prospective Cohort Study. Transplantation and Cellular Therapy. 2021; 27 (9): 788 (doi: 10.1016/j.jtct.2021.06.024).
When administered to patients following allogeneic hematopoietic cell transplantation (allo-HCT) and CD19-based chimeric antigen receptor T (CAR-T) cell therapy, the BNT162b2 mRNA COVID-19 vaccine demonstrated significant immunogenicity, with mostly mild and temporary adverse reactions. Noting the limited data regarding the safety and immunogenicity of the Pfizer-BioNTech COVID-19 vaccine in patients undergoing immune cell therapy, researchers conducted a single-center prospective cohort study to evaluate the vaccine in 66 patients after allo-HCT and 14 patients after CD19-based CAR-T therapy. The vaccine was well-tolerated overall. Cytopenia developed in 12% of patients after the first dose and in 10% after the second, while three instances of graft-versus-host disease exacerbation occurred after each dose. One case of impending graft rejection was thought to be potentially related. Humoral and/or cellular response to the vaccine was observed in 57% of patients following CAR-T infusion and 75% patients after allo-HCT. The Cox regression model correlated a positive humoral response with a longer time from infusion of cells, female gender, and higher CD19+ cells, while the ELISpot test confirmed a positive cellular response with a higher CD4+/CD8+ ratio. Close patient monitoring is recommended in view of the incidence of hematologic events.