Long-lasting Response of Human Circulating T-follicular Helper Cells (cTfh) To Post SARS-CoV-2 mRNA Immunization

The ongoing COVID-19 pandemic underscores the urgent need for effective vaccination strategies to mitigate disease burden. The development of neutralizing antibodies is a critical indicator of host defence mechanisms against life-threatening infectious diseases, such as those caused by SARS-CoV-2. Understanding the fundamental biological mechanisms and substantiality of these antibodies' production is essential for developing effective vaccines, particularly in the face of emerging variants. Circulating T follicular helper (cTfh) cells, which have emerged as significant predictors of neutralizing antibody levels, are of utmost importance in shaping long-term immunity following vaccination. We emphasize the pivotal role of cTfh cells in shaping long-term immunity, providing reassurance about the effectiveness of vaccines. In this study, we elucidate the functions of cTfh cells and their lymphoid counterparts during immune responses to SARS-CoV-2, particularly in the context of spike protein vaccination. We explore the phenotypic diversity of cTfh cells and their potential as biomarkers for development of SARS-CoV-2 vaccine efficacy with long-lasting immunity. The identification of specific cTfh subgroups may inform strategies for enhancing vaccine responses, especially concerning new SARS-CoV-2 variant-specific vaccines. Future research directions will focus on harnessing the predictive capabilities of cTfh cells to optimize vaccine development and improve immunological outcomes against evolving SARS-CoV-2 strains.