Interferon-gamma release assays outcomes in healthy subjects following BNT162b2 mRNA COVID-19 vaccination

Abstract

The pathogenesis of COVID-19 involves both humoral and cellular immunological responses, with cell-mediated immunity being discussed as the primary and most effective immune response to viral infection. It is supposed that COVID-19 vaccines also elicited effective cell immune response, and specifically IFNγ secreted by SARS-CoV-2-specific T-helper 1 and Tcytotoxic cells. Using an interferon-gamma release assay (IGRA) test, we aimed to monitor cellular post-vaccination immunity in healthy subjects vaccinated with BNT162b2 mRNA COVID-19 vaccine (Comirnaty). We tested 37 healthcare workers (mean age 54.3 years, range 28-72, 22 females, 15 males) following COVID-19 mRNA COVID-19 vaccine and 15 healthy unvaccinated native persons as control subjects using QuantiFERON SARS-CoV-2 RUO test, performed approximately 1 month after vaccination. We also measured virus-neutralizing antibodies. Thirty-one out of 37 tested subjects had significantly raised levels of SARS-CoV-2 specific IFNγ against SARS-CoV-2 Ag1 and Ag2 1 month following COVID-19 vaccination. In addition, we found a significant difference between the IFNγ levels in fully vaccinated subjects and the control group (p < 0.01).We also found a substantial correlation (r = 0.9; p < 0.01) between virus-neutralizing antibodies titers and IFNγ concentrations released by T cells. We believe that IGRA tests are an excellent tool to assess the development of a post-vaccination immune response when immunized against SARS-CoV-2. However, IGRA-based tests should be performed within a few weeks following vaccination. Therefore, we can speculate that the application of these tests to assess long-term immune response is debatable. KeywordsCOVID-19 • Interferon-gamma • Interferon-gamma release assay • SARS-CoV-2 • mRNA COVID-19 vaccine • BNT162b2 vaccine • T cytotoxic cells • T helper cells • Cellular immune response • Immune memory

Cellular Immune Response to BNT162b2 mRNA COVID-19 Vaccine in a Large Cohort of Healthcare Workers in a Tertiary Care University Hospital

“…At our knowledge, this is the first study that evaluated T-cell immunity response and explored its potential predictors in a large, representative sample of real-world hospital workers, at a median time elapsed greater than 7 months after second-dose vaccine administration. Few studies have evaluated T-cell responses after two doses of the BNT162b2 vaccine and mainly focused on recently vaccinated individuals (i.e., first two months post-vaccination) or on smaller series [ 19 ]; higher rates of T-cell responsiveness compared to those observed in our study were often observed [ 20 , 21 , 22 ], similar to the rates reported for humoral responses [ 9 ], a finding consistent with a decline in T-cell mediated responses over time observed by others [ 10 , 12 , 23 ] as well as in the present study. However, it is noteworthy that in our study a cellular response ≥ 0.15 IU/mL persists up to 7 months post-vaccination in more than 60–70% of subjects (depending on the Ag), also among subjects without previous SARS-CoV-2 infection ( Table S3 ).…”

Students’ Attitudes toward COVID-19 Vaccination: An Inter-University Study from Bulgaria

“…Bulgaria and the Bulgarian public health system were also in a difficult situation. In this regard, several studies on SARS-CoV-2 infection had been conducted in our country, including: a seroepidemiological survey [ 10 ]; research on clinical characteristics of patients with COVID-19 [ 11 , 12 ]; studies of immune response to SARS-CoV-2 vaccines [ 13 , 14 , 15 ]; research into adverse events of COVID-19 vaccines [ 16 ]; studies dealing with inconclusive SARS-CoV-2 PCR samples [ 17 ]; and studies of liver involvement in children with COVID-19 and multisystem inflammatory syndrome [ 18 ]. The Bulgarian vaccination process started on 26 December 2020.…”

Durability of humoral and cell‐mediated immune response after SARS‐CoV‐2 mRNA vaccine administration

“…The efficacy of two doses of mRNA vaccines for COVID‐19 prevention for a variable length of time has been reported by many authors. 14 , 15 , 16 , 17 , 18 Interesting are the studies on the so‐called “extended vaccine schedules.” 19 , 20 , 21 According to the authors, increasing the interval between the first and second doses from 3 weeks to 11–12 weeks for the Comirnaty vaccine, increased the peak of antibody production.…”