SARS-CoV-2 T-Cell Responses in Allogeneic Hematopoietic Stem Cell Recipients following Two Doses of BNT162b2 mRNA Vaccine

Béatrice Clémenceau; Thierry Guillaume; Marianne Coste-Burel; Pierre Peterlin; Alice Garnier; Amandine Le Bourgeois; Maxime Jullien; Jocelyn Ollier; Audrey Grain; Marie C Béné; Henri Vié; Patrice Chevallier

doi:10.3390/vaccines10030448

SARS-CoV-2 T-Cell Responses in Allogeneic Hematopoietic Stem Cell Recipients following Two Doses of BNT162b2 mRNA Vaccine

Vaccines (Basel). 2022 Mar 14;10(3):448. doi: 10.3390/vaccines10030448.

Authors

Affiliations

¹ CHU Nantes, CRCINA, INSERM, CNRS, Université de Nantes, F-44000 Nantes, France.
² Hematology Department, Nantes University Hospital, Nantes University, F-44000 Nantes, France.
³ Virology Department, Nantes University Hospital, Nantes University, F-44000 Nantes, France.
⁴ Hematology Biology Department, Nantes University Hospital, Nantes University, F-44000 Nantes, France.

Abstract

Background: At variance to humoral responses, cellular immunity after anti-SARS-CoV-2 vaccines has been poorly explored in recipients of allogeneic hematopoietic stem-cell transplantation (Allo-HSCT), especially within the first post-transplant years where immunosuppression is more profound and harmful.

Methods: SARS-CoV-2 Spike protein-specific T-cell responses were explored after two doses of BNT162b2 mRNA vaccine in 45 Allo-HSCT recipients with a median time from transplant of less than 2 years by using INF-γ ELISPOT assay and flow-cytometry enumeration of CD4⁺ and CD8⁺ T lymphocytes with intracellular cytokine production of IFN-γ and TNF-α.

Results: A strong TNF-α⁺ response from SARS-CoV-2-specific CD4⁺ T-cells was detected in a majority of humoral responders (89%) as well as in a consistent population of non-humoral responders (40%).

Conclusions: T-cells are likely to participate in protection against COVID-19 viral infection, even in the absence of detectable antibody response, especially in the first years post-transplant in Allo-HSCT recipients.

Keywords: BNT162b2; CD4+ T cells; CD8+ T cells; COVID 19; IFNγ; SARS-CoV-2 mRNA; TNFα; allogeneic hematopoietic stem cell transplantation; cellular immunity; humoral immunity; vaccine.