Differential Induction of Interferon-Stimulated Genes by Cell-Based Versus Egg-Based Quadrivalent Influenza Vaccines in Children During the 2018-2019 Season

Background: Cell-based quadrivalent-inactivated influenza vaccine has been shown to have higher vaccine effectiveness than traditional egg-based quadrivalent-inactivated influenza vaccine. This is observed despite similar levels of serum hemagglutinin antibodies induced by each vaccine. Results: Cell-based influenza vaccine induced greater interferon-stimulated and innate immune gene activation compared with egg-based influenza vaccine. Participants who seroconverted had increased interferon-signaling activation versus those who did not seroconvert. Conclusions: These data suggest that cell-based influenza vaccine stimulates immune activation differently from egg-based influenza vaccine, shedding light on reported differences in vaccine effectiveness.