Pfizer VS Moderna. 'When the syringe hits the epidermis.' Comparing the vaccines. (Page 2/2) Patrick DEC 22, 12:34 AM Notorio DEC 26, 11:02 PM I've had two vaccines over the last 4 months. The flu vaccine, like noted above, caused zero injection site pain or swelling. A couple weeks later I had the Shingles vaccine, two shots separated by a month I think. No immediate injection site pain or swelling but the Next Day I bumped my arm on something and almost saw stars. It took several days for my arm to become human again. When I had the second shot I had the same response. But it was a small price to pay if it really does protect me from Shingles.