Impact of Immunosuppression on T-cell Responses After mRNA-Based Sars-CoV-2 Vaccination
1National University Centre for Organ Transplantation, National University Hospital, Singapore, Singapore, 2Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore, Singapore
Meeting: 2022 American Transplant Congress
Abstract number: 977
Keywords: COVID-19, T cells, Vaccination
Topic: Clinical Science » Infection Disease » 24 - All Infections (Excluding Kidney & Viral Hepatitis)
Session Information
Session Name: All Infections (Excluding Kidney & Viral Hepatitis) II
Session Type: Poster Abstract
Date: Sunday, June 5, 2022
Session Time: 7:00pm-8:00pm
Presentation Time: 7:00pm-8:00pm
Location: Hynes Halls C & D
*Purpose: Administration of mRNA-based SARS-CoV-2 vaccines confers protection from SARS-CoV-2 infection and reduces its severity in the general population. It has been suggested that mounting a coordinated adaptive immune response characterized by production of neutralizing antibodies and SARS-CoV-2 spike protein-specific T-cells correlates with protection from infection. Studies in organ transplant recipients have demonstrated suboptimal responses after 2 doses of SARS-CoV-2 vaccination; however, the impact of different immunosuppressive regimens (IS) on T-cell responses is not well described. This study prospectively evaluated the impact of IS on T-cell responses in a kidney transplant (KTx) population and compared these to 26 healthy controls.
*Methods: In this single-centre, prospective study, 92 KTx on follow-up at our centre were enrolled after informed consent. T-cell responses were evaluated before and after each of 2 doses of BNT162b2 SARS-CoV-2 vaccine administered 21 days apart: before each dose, 10-14 days after Dose1 and 21-24 days after Dose2. The study population included 69.6% Live-Donor and 30.4% Deceased-Donor KTx. Longitudinal assessment of the quantity of spike-specific T-cells was performed by stimulating whole blood with peptides covering the SARS-CoV-2 spike protein, followed by cytokine (IFN-γ, IL-2) measurement (JCI, Tan et al, 2021). KTx were stratified by maintenance IS into 4 groups and T-cell responses compared between groups.
*Results: As shown (Figures 1A, 1B), in comparison to healthy controls, KTx displayed poor spike-specific T-cell responses as measured by IFN-γ and IL-2 release. Percent responders were significantly lower for KTx vs. healthy controls: 6.5% vs. 92.3% after Dose1 (P<0.00001) and 27.2% vs. 100% after Dose2 respectively. There was a significant impact of different IS regimens (Figure 1C); percent responders after Dose2 were 19%, 43%, 40% and 71% for KTx receiving CNI_MPA_Pred, CNI_Aza_Pred, mTORi and Other regimens respectively (P=0.013).
*Conclusions: Our results highlight the critical role of IS on T-cell responses to SARS-CoV-2 vaccination. In the context of the COVID-19 pandemic, monitoring T-cell and antibody responses over time after vaccination, modulating IS and modifying vaccination strategies are clearly needed to protect this vulnerable population.
To cite this abstract in AMA style:
Wong E, Bert NL, Sran HK, Lim A, D'Costa M, Akalya K, Hang S, Bertoletti A, Vathsala A. Impact of Immunosuppression on T-cell Responses After mRNA-Based Sars-CoV-2 Vaccination [abstract]. Am J Transplant. 2022; 22 (suppl 3). https://atcmeetingabstracts.com/abstract/impact-of-immunosuppression-on-t-cell-responses-after-mrna-based-sars-cov-2-vaccination/. Accessed November 24, 2024.« Back to 2022 American Transplant Congress