Link #1 'Anecdotal'
Link #2 VAERS is a self-reporting database (from the submission form: "Please report all significant adverse events that occur after vaccination of adults and children, even if you are not sure whether the vaccine caused the adverse event.")
Either way, of course be careful with what you decide to put into your body but I just wanted to point out you can find 100 links for and against the flu shot. Both include misinformation, unfortunately, never know what is true and what is false these days. Here is a study
, I haven't checked the credentials of BMJ but do know it is a open-access peer-reviewed medical journal.