There are that many different strains out there that can mutate at any time so I personally stay away from it.
My nan use to get the shot every year and end up feeling like rubbish for 2 weeks, totally run down and couldn't leave the house.
This would happen every time, as apposed to "maybe" catching the flu and end up feeling like rubbish for 2 weeks, totally run down and not being able to leave the house. She ended up getting the flu most times anyway.
Bloody awful the way they're harming the health of the elderly as well as the young.
All in the name of money. Sad times.