What is different about the flu vaccine from year to year?

b/c a small amount of the virus is injected into your body when you get the vaccine-this is so your body can build up antibodies to kill the amount that was injected into you and prevent you from getting it again.some people have weakend immune systems, so when they get the shot-they become sick with the virus instead of their body fighting it off-this is especially true and infants and the elderly.each year, scientists have to decide which strain of the flu people are most likely to become ill with and create the vaccine for it. since the flu is a virus and sometimes can change as it passes from person to person, the shot won’t work for everyone b/c the strain that made them sick isn’t the exact strain they were immunized for.for a majority of the world-it’s effective. and ever since my little girls (ages 5 and 7) got deathly sick with it 3 years ago (they both spent 4 days in the hospital at the same time), i make sure they get their shot every single year.

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i dont think anyone gets flu directly from the flu injection ive had it for the last 6 years and i think its 100% the difference from year to year depends on what strain is going around