• FluTrackers.com Inc. does not provide medical advice. Information on this web site is collected from various internet resources, and the FluTrackers board of directors makes no warranty to the safety, efficacy, correctness or completeness of the information posted on this site by any author or poster. The information collated here is for instructional and/or discussion purposes only and is NOT intended to diagnose or treat any disease, illness, or other medical condition. Every individual reader or poster should seek advice from their personal physician/healthcare practitioner before considering or using any interventions that are discussed on this website. By continuing to access this website you agree to consult your personal physican before using any interventions posted on this website, and you agree to hold harmless FluTrackers.com Inc., the board of directors, the members, and all authors and posters for any effects from use of any medication, supplement, vitamin or other substance, device, intervention, etc. mentioned in posts on this website, or other internet venues referenced in posts on this website.
  • We are not asking for any donations. Do not donate to any entity who says they are raising funds for us.

Mol Biol Rep . COVID-19 vaccination shifts neutrophils toward a mixed activated and regulatory phenotype in patients with severe disease

tetano

Editor, Senior Moderator
Mol Biol Rep


. 2026 Apr 11;53(1):610.
doi: 10.1007/s11033-026-11778-y.
COVID-19 vaccination shifts neutrophils toward a mixed activated and regulatory phenotype in patients with severe disease

Yrna Lorena M de Oliveira[SUP] 1 2 [/SUP], Ayane de S Resende[SUP] 3 [/SUP], Mariana N F de Franca[SUP] 3 [/SUP], Camilla Natália O Santos[SUP] 3 4 5 [/SUP], Lucas S Magalhães[SUP] 4 6 [/SUP], Cristiane B Correa[SUP] 3 7 [/SUP], Priscila L Dos S Almeida[SUP] 3 4 [/SUP], Angela Maria da Silva[SUP] 3 4 [/SUP], Michael W Lipscomb[SUP] 8 [/SUP], Tatiana R de Moura[SUP] 3 4 [/SUP]


Affiliations
Abstract

Background: Dysregulation of the innate immune response to SARS-CoV-2 has been linked to poor outcomes in COVID-19. Neutrophils are key players in this response, displaying distinct functional profiles associated with disease severity. This study investigates how neutrophil phenotypes, and their mediators are modulated in severe COVID-19 following vaccination.
Methods and results: We conducted an observational case-control study using clinical data, serum samples, and circulating neutrophils from patients hospitalized with severe COVID-19. Neutrophils from vaccinated patients exhibited increased expression of surface markers including TREM-1, CD182, HLA-DR, and PD-L1, alongside higher HLA-DR mean fluorescence intensity (MFI). These cells also showed a higher proportion of inflammatory (CD16⁺CD182⁺TREM-1⁺) and immunoregulatory (HLA-DR⁺PD-L1⁺) subsets compared to non-vaccinated individuals. Exploratory principal component analysis (PCA) revealed a trend toward separation of vaccinated and non-vaccinated groups, suggestively driven by inflammatory cytokines (IL-6, TNF-α, GM-CSF, IL-18) and neutrophil surface markers (HLA-DR, PD-L1, TREM-1, CD16).
Conclusions: These findings suggest that prior COVID-19 vaccination is associated with a distinct neutrophil activation profile in patients with severe disease, characterized by the concomitant expression of pro-inflammatory and immunoregulatory markers. This immune phenotype may reflect a more balanced inflammatory response during severe SARS-CoV-2 infection. These findings open avenues for future studies incorporating functional assays and larger, independent cohorts to confirm and extend the biological and clinical relevance of these observations.

Keywords: Innate immunity; Neutrophils; SARS-CoV-2; TREM-1.

 
Back
Top Bottom