Delayed Humoral Response After 2 Doses of the BNT162b2 Vaccine in a Belgian Kidney Transplant Cohort.

We previously published disappointing results regarding the humoral response 28 d after the second dose of the BNT162b2 (Pfizer) vaccine in kidney transplant recipients (KTRs). The present article reports the serological response rate 90 d after the second injection using an immunoassay detecting antibody (Ab) against the spike protein receptor-binding domain (RBD) (Elecsys Anti-SARS-CoV-2, Roche Diagnostics GmbH, Mannheim, Germany; positive threshold ≥0.8 U/mL; upper limit of detection 250 U/mL). This work received institutional review board approval. [.]