Influenza strain-specific T cell responses longitudinally post-vaccination with FluZone

Area of Science:

• Immunology
• Vaccinology
• Virology

Background:

• Influenza viruses cause significant global health burdens despite seasonal vaccination.
• Vaccine effectiveness varies due to host factors and viral evolution.
• Understanding immune responses beyond antibodies is crucial for enhancing vaccine design.

Purpose of the Study:

• To investigate the role of influenza-specific T cells in response to inactivated quadrivalent influenza vaccination.
• To correlate T cell dynamics with humoral immunity and plasma cytokine/chemokine profiles.
• To explore differences in T cell responses between influenza A and B subtypes.

Main Methods:

• Longitudinal measurement of influenza strain-specific T cell responses in 40 participants post-vaccination.
• Restimulation of T cells using live influenza viruses.
• Correlation analysis with hemagglutination inhibition assays and plasma cytokine/chemokine levels.

Main Results:

• Activated and degranulating T cells were detected longitudinally and correlated positively with serological responses.
• Cytokine-producing T cells peaked early post-vaccination, coinciding with elevated IFNγ and CCL4.
• T cell responses showed a stronger correlation with serological outcomes for influenza A than B subtypes.

Conclusions:

• Activated T cells, rather than early cytokine-producing T cells, better reflect longitudinal vaccine-induced humoral immunity.
• Distinct T cell dynamics for influenza A and B subtypes warrant further investigation for vaccine development.
• This research highlights the importance of T cell responses in evaluating and improving influenza vaccines.