Evaluation of circulating leucocyte populations both in subjects with previous SARS-COV-2 infection and in healthy subjects after vaccination

• Published in: Journal of immunological methods Vol. 502; p. 113230
• Main Authors: Grimaldi, Vincenzo, Benincasa, Giuditta, Moccia, Giusi, Sansone, Annunziata, Signoriello, Giuseppe, Napoli, Claudio
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2022
• Subjects: Adult; Aged; Case-Control Studies; CD4-CD8 Ratio; CD4-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - immunology; COVID-19 - blood; COVID-19 - immunology; COVID-19 - prevention & control; COVID-19 - virology; COVID-19 infection; COVID-19 mRNA BNT162b2 (Pfizer-BioNTech) vaccine; COVID-19 Vaccines - administration & dosage; COVID-19 Vaccines - immunology; Cross-Sectional Studies; Female; Flow cytometry characterization; Healthy Volunteers; Humans; Immunity, Innate; Immunogenicity, Vaccine; Immunophenotyping; innate immunity; Male; memory; Memory T Cells - immunology; Middle Aged; SARS-CoV-2 - immunology; Severe acute respiratory syndrome coronavirus 2; T cell immune response; Technical Note; Vaccination; vaccines; virus replication; Flow cytometry characterization; COVID-19 infection; COVID-19 mRNA BNT162b2 (Pfizer-BioNTech) vaccine; T cell immune response
• ISSN: 0022-1759; 1872-7905; 1872-7905
• DOI: 10.1016/j.jim.2022.113230

Innate immune mechanisms are central players in response to the binding of pathogens to pattern-recognition receptors providing a crucial initial block on viral replication. Moreover, innate immune response mobilizes cells of the cellular-mediated immune system, which develop into effector cells that promote viral clearance. Here, we observed circulating leukocyte T cell response in healthy subjects, COVID-19 infected, and in healthy vaccinated subjects. We found a significant CD8+ T cells (p < 0,05) decrease and an augmented CD4+/CD8+ ratio (p < 0,05) in COVID-19 infected group compared with vaccinated subjects. In addition, healthy vaccinated subjects have a significant increased expression of CD8+ T cells, and a reduction of CD4+/CD8+ ratio with respect to subjects previously COVID-19 infected. Central Memory and Terminal Effector Memory cells (TEMRA) increased after vaccine but not among groups.