Had mine last Saturday, been getting them for decades. Never had any reactions. I got the regular shot which contains 4 strains.
My sig other was at the grocery store checking on a product and he noticed the pharmacy had flu shots, so he asked about them. He got the "senior" flu shot that contains 3 strains at a higher dosage. Plus he got a coupon for $5 at the grocery hot bar, you think he had struck gold :) Now with the "senior" flu shot, the pharmacist said it will make you very tired for a couple of hours, and sure enough it did. He's back to normal today.
My parents use to get their flu shots every year even up into their mid-to-late 90's. Not once did they ever have an issue.