Abstract
Influenza viruses continue to undergo antigenic drift and shift, resulting in the need to update existing vaccines annually. Therefore, the development of a universal influenza vaccine has become an urgent global need. This paper reviews the functions of common antigenic targets of influenza vaccines and their advantages and disadvantages in universal vaccine design. We also summarize the common design strategies for universal influenza vaccines, which mainly include the immunofocusing strategy, multi-target combination strategy, T-cell strategy, computationally optimized broadly cross-reactive antigenic strategy (COBRA), and artificial intelligence strategy. In addition, we also sort out the latest research progress of universal influenza vaccines under different technological routes. This will help researchers better grasp the latest developments of universal influenza vaccines.