According to the CDC, people who should get the seasonal vaccine each year are:
Each year a new vaccine is created in anticipation of a certain strain. When the vaccine consists of strains that are similar to the ones that circulate, the vaccine is a good match and provides optimal protection. When the strain differs from the vaccine, effective rates will be impacted. In healthy young adults where the vaccine is a good match, it will be approximately 70%-90% effective.1 Although the vaccine is less effective in populations over 65, it has been demonstrated to reduce the number of deaths and hospitalizations associated with influenza.1