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.