Biomarkers

ICOS-positive and CD38-positive Tfh cells in the blood could help monitor immune responses to prophylactic influenza vaccines. The numbers of ICOS-positive and CD38-positive follicular helper T cells were higher in blood from healthy volunteers vaccinated with Fluarix than in unvaccinated volunteers. In the vaccinated volunteers, 11% of the Tfh cells were specific for influenza antigens, whereas only 0.03% of memory T cells were antigen-specific. Next steps include validating the Tfh cell response to influenza vaccines in elderly, HIV-infected and pediatric cohorts that typically have poor vaccine responses...