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BRIEF RESEARCH REPORT article
Front. Cell. Infect. Microbiol.
Sec. Clinical Infectious Diseases
Volume 15 - 2025 | doi: 10.3389/fcimb.2025.1508120
Different patterns of leukocyte immune responses to infection of ancestral SARS-CoV-2 and its variants
Provisionally accepted- UCONN Health, Farmington, United States
Background: Contributions of leukocytes to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) defense have been reported extensively. However, it remains unclear whether there are different leukocyte responses to ancestral SARS-CoV-2 and its variants.We analyzed peripheral blood leukocyte and subtype concentrations from 575 COVID-19 patients and 950 non-COVID-19 subjects registered at the University of Connecticut John Dempsey Hospital between 2020 and 2022, which covers the ancestral strain, Delta, and Omicron variants.Results: We found that neutrophils, immature granulocytes, and monocytes were elevated, and lymphocytes were reduced after infection. These hyperactive neutrophils/immature granulocytes and suppressed lymphocytes/monocytes were associated with poorer prognosis in ancestral strain infection.Different from the ancestral strain, hyperactive immature granulocytes were not shown in the decedents of Delta infection, and immature granulocyte concentration was not observed to be associated with mortality.In Omicron infection, suppressed lymphocytes and monocytes were not shown in the decedents, and lymphocyte/monocyte concentrations were not associated with mortality.Our findings provided insights into different leukocyte immune responses to ancestral SARS-CoV-2, Delta, and Omicron variants.
Keywords: COVID-19, SARS-CoV-2 Variant, leukocyte, Neutrophil, monocyte, lymphocyte
Received: 08 Oct 2024; Accepted: 27 Mar 2025.
Copyright: © 2025 Wu, Serna, Gan and Fan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Zhichao Fan, UCONN Health, Farmington, United States
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