Impaired humoral and cellular response to primary COVID‐19 vaccination in patients less than 2 years after allogeneic bone marrow transplant

Journal article

Allogeneic haematopoietic stem cell transplant (HSCT) recipients remain at high risk of adverse outcomes from coronavirus disease 2019 (COVID-19) and emerging variants. The optimal prophylactic vaccine strategy for this cohort is not defined. T cell-mediated immunity is a critical component of graft-versus-tumour effect and in determining vaccine immunogenicity. Using validated anti-spike (S) immunoglobulin G (IgG) and S-specific interferon-gamma enzyme-linked immunospot (IFNγ-ELIspot) assays we analysed response to a two-dose vaccination schedule (either BNT162b2 or ChAdOx1) in 33 HSCT recipients at ≤2 years from transplant, alongside vaccine-matched healthy controls (HCs). After two vaccines, infection-naïve HSCT recipients had a significantly lower rate of seroconversion compared to infection-naïve HCs (25/32 HSCT vs. 39/39 HCs no responders) and had lower S-specific T-cell responses. The HSCT recipients who received BNT162b2 had a higher rate of seroconversion compared to ChAdOx1 (89% vs. 74%) and significantly higher anti-S IgG titres (p = 0.022). S-specific T-cell responses were seen after one vaccine in HCs and HSCT recipients. However, two vaccines enhanced S-specific T-cell responses in HCs but not in the majority of HSCT recipients. These data demonstrate limited immunogenicity of two-dose vaccination strategies in HSCT recipients, bolstering evidence of the need for additional boosters and/or alternative prophylactic measures in this group.

Authors: Murray, SM; Barbanti, M; Campbell, C; Brown, A; Chen, L

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: British Journal of Haematology
• Volume: 198
• Issue: 4
• Pages: 668-679
• Publication date: 2022-06-03
• Acceptance date: 2022-06-01
• DOI: 10.1111/bjh.18312
• EISSN: 1365-2141
• ISSN: 0007-1048
• Language: English
• Keywords: Immune system; Antibody; Medicine; Transplantation; Immunology; ELISPOT; Hematopoietic stem cell transplantation; Vaccination; Internal medicine; Immunogenicity; Seroconversion; Adverse effect; T cell