Impact of memory T cells on SARS-CoV-2 vaccine response in hematopoietic stem cell transplant

• Published in: PloS one Vol. 20; no. 4; p. e0320744
• Main Authors: VanOudenhove, Jennifer, Liu, Yuxin, Nelakanti, Raman, Kim, Dongjoo, Busarello, Emma, Ovalle, Natalia Tijaro, Qi, Zhihong, Mamillapalli, Padmavathi, Siddon, Alexa, Bai, Zhiliang, Axtmayer, Alfredo, Corso, Cheryl, Kothari, Shalin, Foss, Francine, Isufi, Iris, Tebaldi, Toma, Gowda, Lohith, Fan, Rong, Seropian, Stuart, Halene, Stephanie
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 28.04.2025; Public Library of Science (PLoS)
• Subjects: Adult; Aged; Antibodies; Antibodies, Viral - blood; Antibodies, Viral - immunology; Antibody response; Antigens; Biology and Life Sciences; Cancer; Chemotherapy; COVID-19; COVID-19 - immunology; COVID-19 - prevention & control; COVID-19 vaccines; COVID-19 Vaccines - immunology; Cytometry; Ethylenediaminetetraacetic acid; Fatalities; Female; Gene sequencing; Health aspects; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Humans; Immune response; Immune response (humoral); Immune system; Immunity, Humoral; Immunoglobulin G; Immunoglobulin G - immunology; Immunological memory; Immunosuppression; Infections; Influence; Lymphocytes; Lymphocytes T; Male; Medicine and Health Sciences; Memory cells; Memory T Cells - immunology; Middle Aged; Mortality; mRNA; Nucleocapsids; Pandemics; Patients; RNA; SARS-CoV-2 - immunology; Severe acute respiratory syndrome coronavirus 2; Spike Glycoprotein, Coronavirus - immunology; Stem cell transplantation; Stem cells; T cells; Transplantation; Vaccination; Vaccines; Viral diseases; United States
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0320744

During the COVID-19 pandemic, hematopoietic stem cell transplant (HSCT) recipients had elevated mortality rates from SARS-CoV-2 infection, ranging between 10–40%. SARS-CoV-2 mRNA vaccines are important tools in preventing severe disease, yet their efficacy post-transplant remains unclear, especially in patients subjected to myeloablative chemotherapy and immunosuppression. We evaluated humoral and adaptive immune responses to the SARS-CoV-2 mRNA vaccination series in 42 HSCT recipients and 5 healthy controls. Post-vaccination responses were assessed by anti-spike IgG and nucleocapsid levels, and antigen specific T cell activity. Immune profiling was performed using clinical flow and mass cytometry. Patients were selected based on humoral and cellular responses for single-cell RNA with TCR and BCR sequencing. Our studies revealed defects in memory T cells that correlated with an absence of cellular response despite nearly universal humoral response. Several patients with a robust antibody response developed COVID-19 infection, but none developed severe disease or died from the infection.