Study explores how the immune system fine tunes SARS-CoV-2 vaccine antibody diversity and affinity

After vaccination against COVID-19, follicular T cells must strike a fine balance to help optimize immunity, a new study in preclinical models finds. Investigators from the Brigham studied the roles of follicular helper T (Tfh) cells and follicular regulatory T (Tfr) cells after vaccination by perturbing these cell types in mice. They found that the two cell types helped to balance out antibody diversity and affinity, and deleting either type of cell altered the immune response after vaccine boosting. Additionally, the team found important differences in aged mice, which have altered Tfh and Tfr cells. The authors note that although this work was performed in preclinical models using a non-FDA approved vaccine formulation, the immunologic principals likely extend to current and future clinical vaccines. 

“This work lays a foundation for new ways to enhance SARS-CoV-2 vaccine effectiveness by targeting specific cells of the immune system,” said corresponding author Peter Sage, PhD, of the Transplantation Research Center in the Brigham’s Renal Division. “This work uncovers how vaccine responses are altered in the elderly, providing a framework for new strategies to enhance vaccine effectiveness later in life.”

Read more in Cell Reports.