Body Wise

Should You Insist on a Mercury-Free Flu Shot?

by Robert W. Sears, MD

Almost 10 years ago the realization that millions of infants were being overloaded with mercury from childhood vaccinations rocked the U.S. medical community.

These vaccinations had used thimerosal, a mercury-containing preservative, since the 1930s. As the number of recommended vaccines grew, so did the exposure to mercury, until a baby could get up to 80 times the recommended safety limit in one round of shots. This would be repeated at several consecutive infant checkups.

In unborn and young children, high mercury levels can cause delayed development, memory and attention problems, decreased IQ or mental retardation. It can similarly impair adults and can also increase the risk of heart attacks.

Medical policy-makers and vaccine manufacturers scrambled to remove mercury from vaccines, and by the end of 2002 mercury was a thing of the past. Or was it?

Still in Some Flu Vaccines
Mercury has been removed from all vaccines except for some formulations of the flu vaccine (and some plain tetanus shots). But when you take your child in to the doctor's office for a flu shot this year, which is now recommended for all kids age 6 months to 5 years at the start of every flu season, you might not have a choice about mercury.

The flu vaccine is always in short supply. Most doctors have to take whatever is available from their vaccine suppliers. So your doctor might not have any mercury-free flu shots to offer. For the upcoming flu season, here are the brands your doctor can choose from:

• Fluvirin brand is approved for kids age 4 and older and adults. Mercury is used in manufacturing, but then filtered out.

• Fluarix and FluLaval are for adults only. Fluarix filters out the mercury too, but FluLaval contains a full dose of mercury (25 micrograms).

â?¢ Fluzone is the only brand that is used for infants age 6 to 35 months. The half-dose infant and single-dose toddler vials are mercury-free, but there isn't enough to go around. Only babies that get the shot at the start of the season are guaranteed a mercury-free shot. Fluzone also makes a small supply of mercury-free single-dose flu shots for older children and adults, so only the first kids in line will get one. Most Fluzone is manufactured in large bottles of flu shots for all ages, and each shot out of these 10-dose bottles has a full 25 micrograms of mercury.

Ask To See
As a parent, how can you be sure your child is getting a mercury-free flu shot? Ask the nurse to physically show you the bottle as she prepares the shot. If it is Fluzone brand, and it is a small, single-dose vial or it's in a pre-filled single-dose syringe so that the nurse doesn't have to draw it up, then it is mercury-free.

If it is Fluvirin or Fluarix brand, then there is only a barely detectable, insignificant amount of mercury.

If it is FluLaval brand, or the large 10-dose bottle of Fluzone, then you can just say no, depending on your view of the risks to your child.

What should you do if your doctor only has shots with the full dose of mercury left? First, children age 6 or older don't even need to get a flu vaccine, since it is only recommended for younger kids. Second, kids age 2 and older can get the mercury-free nasal spray flu vaccine instead. Third, you can search elsewhere for any left-over mercury-free shots at other doctors' offices or clinics. And finally, you can simply decide to do without the flu vaccine for that year.

Risks of No Shot
What? Skip the flu shot? Don't tens of thousands of people die each year from the flu, most of them infants and the elderly? How can parents even think about not getting their baby protected from this deadly virus?

The actual number of childhood fatalities from the flu is very small (although tragic). The National Center for Health Statistics reports that flu deaths in children of all ages has been less than 100 each year for many years now, except for the 2003-2004 season, when 150 deaths occurred.

While flu fatalities may be preventable with the vaccine, you shouldn't live in fear that it's going to sweep through your community, killing children left and right.
Do you need to worry about mercury in the first place? Researchers battle back and forth over this issue. We’ve known for decades that mercury is toxic to the brain and body tissues. But whether or not the amount in vaccines is enough to cause damage is still up in the air.

Mercury Risk: Jury’s Out
Some research shows there is enough evidence of harm; other studies have found there is not enough proof that the mercury in vaccines is dangerous. However, no study has yet to prove for certain that this mercury is safe.

Because we just don't know yet for sure, in my opinion it's better to just skip the flu shot (unless you have a chronic medical condition that makes the flu risky for you) if you can't find one without mercury.

This is especially true for pregnant women. No one wants a developing fetus to be exposed to mercury. And it's also true for young kids whose brains are constantly growing. In the coming years, the hope is that we will have more mercury-free flu shots to cover our nation's infants.

“Dr. Bob” Sears is a pediatrician and author in the best-selling Sears Parenting Library, along with his father, William Sears, MD and brother, James M. Sears, MD. Find
online updates of his latest book,
The Vaccine Book: Making the Right Decision for Your Child (Little Brown, $13.99) at