Call for a paradigm shift in the design of universal influenza vaccines by harnessing multiple correlates of protection.

To develop a truly universal influenza vaccine, multiple correlates of protection should be considered, including antibody responses and T cell immunity. Balanced induction of neutralizing antibodies, antibody effector functions, and T cell immunity will contribute to the most effective vaccination strategy. Live-attenuated influenza vaccines provide an attractive platform to improve the breadth and potency of vaccines for broader protection.