vaccine volunteer has complained of a "really sick feeling" after taking part in the Pfizer study. Eric Gross has spoken out about his experience after receiving two doses of the jab.Speaking during TMZ Live, Eric claims the first injection made his arm sore, however the second dose hit him hard.He said: "The first shot is not bad, the first one you wake up and you're like a little bit icky, you feel like you're kind of sick and you're fine, it goes away."The shot in your arm though, it was the most painful as far as soreness, when you lift your arm it was really sore – that was after both times."The second shot makes you a lot sicker – when I got the second shot, about six hours after I got the shot till about 12 hours I was really sick,.