The quest for a universal flu vaccine has been a long and challenging journey for scientists. Each year, millions of people are vaccinated to protect against severe respiratory illnesses caused by influenza viruses. However, current vaccines vary in effectiveness, offering between 10% and 60% protection depending on the strain and season. This inconsistency arises because the flu virus mutates rapidly, making it difficult to predict which strains will dominate each season. As a result, seasonal vaccines often fail to protect against the most virulent flu strains. Researchers are now exploring …