According to the Colorado Flu Report dated Feb. 17, below are influenza-associated hospitalizations by age group. Numbers are the rate per 100,000. The vaccine can "reduce flu illnesses, doctors’ visits, and missed work and school due to flu, as well as prevent flu-related hospitalizations," the CDC's website says. Rare exceptions include people with severe, life-threatening allergies to the flu vaccine or any ingredient in the vaccine. This might include gelatin, antibiotics or other ingredients.