PB0047 - COVID-19 infection-associated platelet and neutrophil activation is blunted by previous anti-SARS-CoV-2 vaccination.

Sunday, June 25, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

Eleonora Petito, Post Doc

Post Doc
Department of Medicine and Surgery, Section of Internal and Cardiovascular Medicine, University of Perugia
Perugia, Umbria, Italy

Co-Author(s)

LF

Laura Franco

Dr.
Department of Medicine and Surgery, Section of Internal and Cardiovascular Medicine, University of Perugia
Perugia, Umbria, Italy
EF

Emanuela Falcinelli

Post Doc
Department of Medicine and Surgery, Section of Internal and Cardiovascular Medicine, University of Perugia
Perugia, Umbria, Italy
Giuseppe Guglielmini, PhD

Biologist, PhD
Department of Medicine and Surgery, Section of Internal and Cardiovascular Medicine, University of Perugia
Perugia, Umbria, Italy
CC

Chiara Conti

PhD student
Department of Medicine and Surgery, Section of Internal and Cardiovascular Medicine, University of Perugia
Perugia, Umbria, Italy
Francesca Tondi, MS

Graduate student
University of Perugia, Departement of Medicine and Surgery, Section of Internal and Cardiovascular Medicine
Perugia, Umbria, Italy
GV

Gaetano Vaudo

Prof.
Unit of Internal Medicine, Terni University Hospital, 05100, Terni , Italy
Terni, Umbria, Italy
UP

Ugo Paliani

Dr.
Division of Internal Medicine, ASL 1 Umbria, 06012, Città di Castello, Italy
Città di Castello, Umbria, Italy
CB

Cecilia Becattini, PhD

Professor
University of Perugia
Perugia, Umbria, Italy
Paolo Gresele, MD, PhD

Professor
Dept. of Medicine and Surgery, University of Perugia
Perugia, Umbria, Italy

Background: The effectiveness of SARS-CoV-2 vaccination in preventing COVID-19 or in reducing severe illness in subjects with breakthrough infection has been unequivocally shown. In vivo platelet and neutrophil activation are associated with COVID-19 outcome and thrombotic complications.

Aims: To assess if subjects who despite vaccination undergo breakthrough COVID-19 are protected from SARS CoV-2-induced platelet and neutrophil activation.

Methods: Venous blood was collected from 42 patients hospitalized for COVID-19 (14 of whom previously vaccinated and 28, age- and sex-matched, not) and 12 healthy subjects (HS) matched for age, sex and clinical features. Platelet activation was assessed measuring platelet-derived microparticles by flow-cytometry and soluble P-selectin by ELISA; neutrophil activation by citrullinated histone H3 by ELISA, neutrophil-derived microparticles by flow-cytometry, MMP-9 and MMP-9/NGAL release by zymography.

Results: The SOFA score, comorbidities and COVID-19 treatment did not differ between vaccinated and unvaccinated COVID-19 patients. The neutrophil count was significantly higher in unvaccinated, but not in vaccinated, COVID-19 patients compared to HS. Soluble P-selectin, neutrophil-derived microvesicles, the NET biomarker citrullinated histone H3, and the neutrophil granule release marker MMP-9/NGAL were significantly higher in unvaccinated, but not in vaccinated, COVID-19 patients compared to HS (Figure 1A-F). Despite breakthrough infection, previous anti-SARS-CoV-2 vaccination improved COVID-19 outcome, given that thrombotic events, hospitalizations in ICU and deaths occurred in 53.5% of unvaccinated and 14.2% of vaccinated COVID-19 patients (χ2: p=0.01).

Conclusion(s): Despite similar disease severity at hospitalization, previous vaccination blunts COVID-19-associated in vivo platelet and neutrophil activation, parameters correlated with thrombotic complications and worse COVID-19 outcome. Our data are in agreement with recent reports that vaccination is associated with a reduced risk of acute myocardial infarction, ischemic stroke and venous thromboembolism in patients with breakthrough COVID-19 infection, and further support the importance of vaccine administration.