Re-vaccination against SARS-CoV-2 in allogeneic HSCT patients: Repeated primary vaccine doses increase seroconversion rates

Br J Haematol. 2024 Nov;205(5):1720-1726. doi: 10.1111/bjh.19780. Epub 2024 Sep 23.

Abstract

Patients with haematological malignancies often exhibit reduced antibody responses to severe acute respiratory syndrome-related coronavirus vaccines, especially those who have undergone allogeneic haematopoietic stem cell transplantation (HSCT). Limited data exist on vaccine efficacy in this group. In a retrospective analysis of 75 post-HSCT patients, we assessed serologic responses to one to four doses of Pfizer-BioNTech (PB), AstraZeneca (AZ) or Moderna (MU) vaccines within 2 years post-transplant. Seroconversion rates were 50.7%, 78%, 79% and 83% after the first to fourth doses respectively. The median time from allograft to first re-vaccination was 145 days (range 79-700). Failure to respond to the first vaccine dose was linked to acute GVHD (p = 0.042) and rituximab treatment within 12 months (p = 0.019). A trend was observed with chronic GVHD and seroconversion failure after the second (p = 0.07) and third (p = 0.09) doses. Patients vaccinated before HSCT showed better antibody responses post-transplant (p = 0.019). Coronavirus disease 2019 incidence was 16%, with 17% hospitalized and one death (8%). Despite low initial seroconversion rates post-HSCT, antibody responses improved after the second dose. Early full re-vaccination and boosters post-HSCT are recommended to reduce mortality. Rituximab use and active GVHD were identified as risk factors, warranting further investigation.

Keywords: HSC transplantation; SARS‐CoV‐2; vaccines.

MeSH terms

  • Adult
  • Aged
  • Antibodies, Viral / blood
  • COVID-19 Vaccines* / administration & dosage
  • COVID-19 Vaccines* / immunology
  • COVID-19* / immunology
  • COVID-19* / prevention & control
  • Female
  • Graft vs Host Disease / etiology
  • Graft vs Host Disease / prevention & control
  • Hematologic Neoplasms / immunology
  • Hematologic Neoplasms / therapy
  • Hematopoietic Stem Cell Transplantation* / adverse effects
  • Humans
  • Immunization, Secondary
  • Male
  • Middle Aged
  • Retrospective Studies
  • SARS-CoV-2* / immunology
  • Seroconversion*
  • Transplantation, Homologous
  • Vaccination

Substances

  • COVID-19 Vaccines
  • Antibodies, Viral