European Hematology Association: Humoral Response to the Pfizer/BioNTech BNT162b2 Vaccine Is Impaired in Patients Receiving CAR-T or High-Intensity Immunosuppressive Therapy

THE HAGUE, Netherlands, June 12, 2021 /PRNewswire/ -- The Pfizer/BioNTech BNT162b2 vaccine has been approved for the prevention of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and is recommended for immunosuppressed patients. However, its efficacy and safety in patients undergoing immunologic cell therapy have not been well-documented. In this study, we evaluated the efficacy and safety of the BNT162b2 vaccine in patients that underwent hematopoietic cell transplantation (HCT) and chimeric antigen receptor (CAR)-T therapy. We prospectively followed 79 vaccinated patients who were actively treated at the Tel Aviv Sourasky Medical Center and monitored the safety profile and the humoral immune response to the vaccine.

Overall, the vaccine was well-tolerated and all adverse events resolved within a few days except for one secondary graft rejection, which is still under investigation. We observed that only 36% of patients who received CAR-T therapy developed a humoral antibody response compared with 81% of patients who underwent allogeneic HCT. In addition, patients with B cell aplasia and those who received the vaccine shortly after infusion of cells were less likely to develop antibodies. Taken together, these data demonstrate that the humoral response to the BNT162b2 vaccine is significantly impaired in patients receiving CAR-T , as opposed to those after allogeneic HCT who had a good response.

Presenter:          Professor Ron Ram

Affiliation:          BMT Unit, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel

Abstract:              #S285  SAFETY AND EFFICACY OF THE BNT162B2 MRNA COVID-19 VACCINE IN PATIENTS AFTER ALLOGENEIC HCT AND CD19-BASED CAR-T THERAPY – A SINGLE CENTER PROSPECTIVE COHORT STUDY

About the EHA Annual Congress: Every June, EHA organizes its Annual Congress in a major European city. This year, due to the persisting COVID19 pandemic, EHA organizes a virtual Congress for the second time. The Congress is aimed at health professionals working in or interested in the field of hematology. The scientific program topics range from stem cell physiology and development to leukemia; lymphoma; diagnosis and treatment; red blood cells; white blood cells and platelet disorders; hemophilia and myeloma; thrombosis and bleeding disorders; as well as transfusion and stem cell transplantation.

Website: www.ehaweb.org

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