Influenza viruses remain a formidable challenge to global public health, causing annual epidemics and intermittent pandemics, and resulting in over 3 million severe infections with 290,000–650,000 deaths annually. It also frequently causes large-scale outbreaks that spread across countries or continents, and global warming and extreme weather events have intensified the spread and impact of the disease. While vaccination is the cornerstone of control on influenza, the continuous antigenic drift and shift in viruses relentlessly outpace traditional vaccine strategies. The collection of articles presented in this Special Issue provides a compelling snapshot of the current state of influenza vaccine research, highlighting a decisive shift from merely inducing neutralizing antibodies towards a more holistic understanding of immunity, host factors, and vaccine deployment. These studies collectively advance the field by exploring conserved epitopes for universal protection, novel routes of administration, the critical role of non-neutralizing functions, the benefits of vaccination beyond infection prevention, the intricate influence of circadian biology on vaccine success, and the global influenza pandemic preparedness based on vaccine development.