2 research outputs found
Humoral and cellular immune response in patients with hematological disorders after two doses of BNT162b2 mRNA COVIDā19 vaccine: A singleācenter prospective observational study (NCT05074706)
Abstract Hematological patients at higher risk of severe COVIDā19 were excluded from the severe acute respiratory syndrome coronavirus 2 (SARSāCoVā2) vaccine trials. In this singleācenter observational prospective study (NCT05074706), we evaluate immune response in the hematological patients followed at the Hematological Division of San Gerardo Hospital, Monza (Italy) deemed to be severely immunosuppressed after vaccination with two doses of the BNT162b2 vaccine. AntiāSARSāCoVā2 immunoglobulin G titers above the cutoff value of 33.8 BAU/ml were detected in 303 (80.2%) out of the 378 patients enrolled. Patients with lymphoproliferative disorders had a significant lower probability of immunization (43.2% vs. 88.4%, pĀ <Ā 0.001). Patients treated with antiāCD20 showed a significantly lower probability of immunization compared to all other treatments (21.4%, pĀ <Ā 0.0001). Among 69 patients who failed seroconversion, 15 patients (22.7%) showed a positive Tācell response. Patients previously treated with antiāCD20 were 2.4 times more likely to test positive for Tācell responses (pĀ =Ā 0.014). Within a followāup of 9 months from the second COVIDā19 vaccination, symptomatic SARSāCoVā2 infections were reported by 20 patients (5.3%) and four of them required hospitalization. Successful serological or Tācellāmediated immunization conferred protection from symptomatic COVIDā19. Patients treated with antiāCD20 who were not seroconverted after vaccination might still be protected from COVIDā19 due to the Tācell immune response