Robust SARS-CoV-2 T cell responses with common TCRαß motifs toward COVID-19 vaccines in patients with hematological malignancy impacting B cells.

Immunocompromised hematology patients are vulnerable to severe COVID-19 and respond poorly to vaccination. Relative deficits in immunity are, however, unclear, especially after 3 vaccine doses. We evaluated immune responses in hematology patients across three COVID-19 vaccination doses. Seropositivity was low after a first dose of BNT162b2 and ChAdOx1 (∼26%), increased to 59%-75% after a second dose, and increased to 85% after a third dose. While prototypical antibody-secreting cells (ASCs) and T follicular helper (Tfh) cell responses were elicited in healthy participants, hematology patients showed prolonged ASCs and skewed Tfh2/17 responses. Importantly, vaccine-induced expansions of spike-specific and peptide-HLA tetramer-specific CD4+/CD8+ T cells, together with their T cell receptor (TCR) repertoires, were robust in hematology patients, irrespective of B cell numbers, and comparable to healthy participants. Vaccinated patients with breakthrough infections developed higher antibody responses, while T cell responses were comparable to healthy groups. COVID-19 vaccination induces robust T cell immunity in hematology patients of varying diseases and treatments irrespective of B cell numbers and antibody response.

ANZTCT Position Statement: COVID-19 Management in Haematopoietic Stem Cell Transplant and Chimeric Antigen Receptor T cell Patients.

Patients post haematopoietic stem cell transplant or CAR-T cell therapy face significant risk of morbidity and mortality from SARS-CoV19, due to their immunosuppressed state. As case numbers in Australia and New Zealand continue to rise, guidance on management in this high-risk population is needed. Whilst we have learnt much from international colleagues who faced high infection rates early in the pandemic, guidance relevant to local health system structures, medication availability and emerging therapies is essential to equip physicians to optimally manage our patients. This article is protected by copyright. All rights reserved.