Q. Do vaccines still contain mercury? What about the flu vaccine?
In 2001, the FDA required manufacturers to discontinue using mercury preservative for ALL routine childhood vaccines. Period.
Many vaccines, like Measles Mumps and Rubella (MMR), have NEVER contained mercury preservatives. Nor is mercury used in the production process for MMR. However, there are four vaccines on the market that still use mercury preservative in the manufacturing process--the mercury is then removed from the final vaccine.
Because the flu vaccine is considered optional, some manufacturers continue to make multi-dose vials of flu vaccine with mercury preservative. However, there are other flu vaccines that are free of mercury preservatives-and many pediatricians give these shots for children.
Let's do a reality check here: a tuna sandwich has five times more mercury than one dose of flu vaccine.
As a doctor, I am much more concerned about mercury exposure in the environment-particularly in food (like that tuna fish sandwich). So if you are worried about mercury exposure, consider this: there's mercury in breast milk. A baby gets 25 times more mercury by breastfeeding for six months than in a single dose of flu vaccine. Breast milk contains between 1.4 and 1.7 micrograms of methyl mercury per liter. If you assume that a baby is breast-fed exclusively up until six months of age, that baby will consume about 360 micrograms of methyl mercury. That's twice the amount of mercury that was ever contained in vaccines and 25 times the quantity of mercury contained in the influenza vaccine.
A quick chemistry lesson: certain compounds have completely different properties even though they have similar sounding names. For instance, there are TWO types of mercury: methyl mercury and ethyl mercury. The type of mercury that has raised health concerns is methyl mercury. Methyl mercury is a small molecule that can get into the brain and takes almost two months to break down. High concentrations of methyl mercury can be found in tuna, swordfish and shark from contaminated waters.
Now, let's contrast that with ETHYL mercury, which is/was the type of mercury used in vaccine preservatives. Ethyl mercury (thimerosal is an example) is rapidly eliminated from the body within a week. Compared to methyl mercury, ethyl mercury is a much larger molecule that cannot enter the brain.
Ideally, it would be nice to remove ALL mercury preservatives from flu vaccines -- so we could put this controversy to rest. The problem: at this time, the only way to manufacture the huge quantity of flu vaccine needed each year requires using mercury preservatives. Hopefully, vaccine makers will figure out a way to eliminate mercury from all vaccines in the future-so any concerns can finally be put to rest.