More food for thought.
Strangely enough, for a short time I worked as a hospital porter during my early twenties, and automatically qualified for the Flu jab. This was the first time I noticed a very minute continuous nervous tick that was sufficient for me to say to a nurse that I thought I had Parkinson's, when she described what was wrong with a bed bound PD patient on the men's ward.
Back then, once the minor Flu symptoms went, I forgot all about the little misses in my rhythm, yet twenty plus years later it now figures in my thoughts once more. So while considering the possibility of a Flu jab in the future, I am edging more towards just going with a Vitamin D dose or two next winter to help arm me against future bouts.
It will be interesting to know what others think and have experienced.