Speakers - 2025

Biography

Experienced academic and healthcare leader with 20+ years in Medical Microbiology, specializing in clinical diagnostics, antimicrobial resistance, and healthcare-associated infections. Associate Professor at NKUA’s Medical School, teaching and mentoring students since 2009. Published 52 papers with 1,587 citations and an h-index of 24 (Scopus, 2024). Held key leadership roles in hospitals and biomedicine organizations. Passionate about advancing clinical microbiology, infection control, and medical education through research, innovation, and collaborative teamwork in academia and healthcare.

Abstract

Abstract

Background: The essential management of vaccination schedules requires a thorough knowledge and measurement of the individual's immunoprotection level, interaction, and persistency at both humoral and cellular levels following SARS-CoV-2 vaccination.
The goal of this study was to investigate the possible relationship between the levels and duration of SARS-CoV-2 T cell response and IgG measurements in a particular cohort consisting of individuals who were COVID-19 naive and had received SARS-CoV-2 vaccination.

Methods: We performed a retrospective descriptive analysis utilizing data retrieved from the electronic medical records of consecutive COVID-19 naïve and vaccinated adult individuals who underwent COVID-19 immunity screening at BIOIATRIKI private healthcare center from September 2021 to September 2022. T-cell response was evaluated using the IGRA methodology T-SPOT®. COVID (Oxford Immunotec, Oxfordshire, UK). SARS-CoV-2 IgG antibody levels were evaluated with SARS-CoV-2 IgG II Quant assay (Abbott Laboratories).

Results:

A cohort of 262 individuals, comprising 148 females (56.5%) and 114 males (43.5%), with ages ranging from 17 to 92 years (mean age: 59.47±15.5 years), were included in the study.

The mean time elapsed post-exposure/vaccination for all participants was 137.12 ± 78.7 days (range: 14-364 days). Individuals with a positive antibody response demonstrated statistically significant higher T-SPOT results compared to those with undetectable antibody levels. Specifically, the mean rank was 125.7 in set A and 158.73 in group B (Mann-Whitney Test, p = 0.006). No significant difference was observed between the two groups in the time period post-vaccination, with mean times after vaccination being 136.38±78.68 days in group A and 140.6±79.5 days in group B (T test, p = 0.74).

Conclusions: Our findings indicate that the activation of humoral immunity following SARS-CoV-2 vaccination is associated with higher levels of produced cellular immunity compared to low or undetectable antibody levels.