Common misconception, no there isn't. The vaccines target whole strains and it is extremely rare for a new one to show up. What happens is, every spring the best guess is made about which strains will be most common in the coming fall, then the summer is spent manufacturing the existing vaccines for those strains. For cost and compatibility reasons, yearly shots only contain a small handful of the possible flu vaccines, so you're supposed to get them every year to ensure you've gotten one that includes the currently expected dominant strains.
Common misconception, no there isn't. The vaccines target whole strains and it is extremely rare for a new one to show up. What happens is, every spring the best guess is made about which strains will be most common in the coming fall, then the summer is spent manufacturing the existing vaccines for those strains. For cost and compatibility reasons, yearly shots only contain a small handful of the possible flu vaccines, so you're supposed to get them every year to ensure you've gotten one that includes the currently expected dominant strains.