Mercury (or rather, Thiomersal) hasn't been used in the vast majority of vaccines since the 90s. It was completely safe as far as we know, but was removed as a

Mercury (or rather, Thiomersal) hasn't been used in the vast majority of vaccines since the 90s. It was completely safe as far as we know, but was removed as a precautionary measure during a push to remove all sources of mercury from food and drugs.