# Optimizing SARS-CoV-2 vaccine responses in kidney transplant recipients: an urgent need

## TL;DR

This study shows that kidney transplant recipients have weaker immune responses to SARS-CoV-2 vaccines compared to healthy people, highlighting the need for better vaccine strategies for this group.

## Contribution

The study provides new insights into both serological and cellular immune responses in kidney transplant recipients after SARS-CoV-2 vaccination.

## Key findings

- Kidney transplant recipients had significantly lower antibody and T cell responses to SARS-CoV-2 vaccines.
- Transplant recipients showed reduced IFN-γ secretion when exposed to SARS-CoV-2 spike peptides.
- These findings suggest compromised immunity in transplant recipients post-vaccination.

## Abstract

Kidney transplant recipients (KTRs) have been identified as a population at increased risk for severe SARS-CoV-2 infection outcomes. This study focused on understanding the immune response of KTRs post-vaccination, specifically examining both serological and cellular responses to the SARS-CoV-2 vaccine. Thirteen individuals, including seven KTRs and six healthy donors, were evaluated for antibody levels and T cell responses post-vaccination. The study revealed that KTRs had significantly lower serological responses, including reduced anti-receptor binding domain (RBD) binding antibodies and neutralizing antibodies against the Wuhan, Delta, and Omicron BA.2 strains. Additionally, KTRs demonstrated weaker CD8 T cell cytotoxic responses and lower Th1 cytokine secretion, particularly IFN-γ, after stimulation with variant spike peptide pools. These findings highlight the compromised immunity in KTRs post-vaccination and underscore the need for tailored strategies to bolster immune responses in this vulnerable group. Further investigations are warranted into the mechanisms underlying reduced vaccine efficacy in KTRs and potential therapeutic interventions.

Some studies have revealed that KTRs had lower serological response against SARS-CoV-2 than healthy people. Nevertheless, limited studies investigate the cellular response against SARS-CoV-2 in KTRs receiving SARS-CoV-2 vaccines. Here, we found that KTRs have lower serological and cellular responses. Moreover, we found that KTRs had a significantly lower IFN-γ secretion than healthy individuals when their PBMCs were stimulated with SARS-CoV-2 spike peptide pools. Thus, our findings suggested that additional strategies are needed to enhance KTR immunity triggered by the vaccine.