When we went for the H1N1 shot, they did not have any without mercury. My DD and I both got the shot - and the next week a lot of her friends ended up with 104 temperatures and 1/5 of the school was out sick. My DD had a simple cold. I am glad we got the shots but that mercury does make me a bit nervous. I listen to the arguments about it but also heard it has the same amount of mercury as a can of tuna fish. Because they only had that one shot, I had to make a judgment call right then and there.