Antibody and T Cell Response to SARS-CoV-2 Messenger RNA BNT162b2 Vaccine in Kidney Transplant Recipients and Hemodialysis Patients.

Bertrand, Dominique; Hamzaoui, Mouad; Lemée, Veronique; Lamulle, Julie; Hanoy, Melanie; Laurent, Charlotte; Lebourg, Ludivine; Etienne, Isabelle; Lemoine, Mathilde; Le Roy, Frank; Nezam, Dorian; Plantier, Jean-Christophe; Boyer, Olivier; Guerrot, Dominique; Candon, Sophie

Background. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with a high rate of mortality in patients with end stage renal disease and vaccination is hoped to prevent infection. Methods. Between January 18, and February 24, 2021, 225 kidney transplant recipients (KTR) and 45 hemodialysis patients (HDP) received two injections of mRNA BNT162b2 vaccine. The post-vaccinal humoral and cellular response was explored in the first 45 KTR and 10 HDP. Results. After the second dose, 8 HDP (88.9%) and 8 KTR (17.8%) developed anti-spike SARS-CoV-2 antibodies (p<0.0001). Median titer of antibodies in responders was 1052 AU/mL (IQR: 515-2689) in HDP and 671 AU/mL (IQR: 172-1523) in KTR (p=0.4). Nine HDP (100%) and 26 KTR (57.8%) showed a specific T cell response (p=0.06) after the second injection. In responders, median numbers of spike-reactive T cells were 305 SFC/106 CD3+ T cells (IQR: 95-947) in HDP and 212 SFC/106 CD3+ T cells (IQR: 61-330) in KTR (p=0.4). In KTR, the immune response to BNT162b2 seemed influenced by the immunosuppressive regimen, particularly tacrolimus or belatacept. Conclusion. Immunization with BNT162b2 seems more efficient in HDP, indicating that vaccination should be highly recommended in these patients awaiting a transplant. However, the current vaccinal strategy for KTR may not provide effective protection against COVID-19 and will likely need to be improved.