flu vaccine development

Flu vaccine development involves identifying the most common flu strains predicted to circulate each season. Scientists grow these virus parts in labs, then process them into a safe, inactivated or weakened form. These vaccine components stimulate the immune system to recognize and fight the actual flu virus if encountered later. The process usually takes about six months, balancing scientific prediction, manufacturing, and testing to ensure safety and effectiveness. Annual updates are common because flu viruses change rapidly, requiring new vaccines tailored to the most relevant strains each season.