Thimerosal is an ethylmercury-based preservative – different from the kind of mercury found in seafood, called methylmercury. Ethylmercury has a shorter half-life in the body. The amount of ethylmercury contained in a flu vaccine (25 micrograms) is about half of that contained in a 3oz serving of canned tuna fish (40 micrograms).

lol. Saving Americans from the equivalent of 1.5oz of tuna.