Feeling stuck: Mercury in kids flu shots focus of debate
By JUDY L. THOMAS
Millions of America's health-conscious parents are lining up their children
for this year's flu shot.
But many are unaware that some doses contain mercury, a potent poison. Even
more do not know that a mercury-free flu shot exists. That lack of
understanding has driven down demand and reduced the availability of
mercury-free vaccine this year.
The federal Centers for Disease Control and Prevention recommends that all
children ages 6 months to 23 months get a flu shot. Citing many studies, the
agency insists that flu shots containing mercury are safe.
CDC officials also recommend that parents who want a mercury-free shot for
their children, only to find none is available, should still get them
"We want to protect people against influenza, and vaccination is the very
best way to do that," said Jeanne Santoli of the CDC's Immunization Services
Critics disagree, saying that mercury - which is used to prevent
contamination in multidose flu vaccines - is causing an alarming rise in
autism and other neurodevelopmental disorders.
"I think it's absolutely criminal to give mercury to an infant," said Boyd
Haley, an expert on mercury toxicity and a vocal critic of the CDC.
As the debate continues, the company that makes most flu vaccines says there
is a waiting list this year for health agencies that want vaccines that
contain mercury. Meanwhile, the company is scaling back production of its
mercury-free vaccine, The Kansas City Star has learned.
Only Sanofi Pasteur is approved to market a new mercury-free pediatric flu
vaccine. Spokesman Len Lavenda said the company had planned to make 8
million doses of the mercury-free version of its Fluzone vaccine for this
flu season but has cut back to 6 million doses.
The CDC estimates it would take about 12 million doses to vaccinate all
children ages 6 months to 23 months.
"We were prepared to more than double the quantity this year, but demand for
the product didn't warrant producing that much," Lavenda said. "While we
have on several occasions sold out all of our preservative-containing
(mercury) vaccine in the last several years, we have never sold out all of
our preservative-free vaccine."
Lavenda said he had no idea why health officials were not ordering more
In 1999, the CDC, the U.S. Public Health Service and the American Academy of
Pediatrics recommended removing mercury from other childhood vaccines as a
precaution after concerns were raised that children may be receiving too
much mercury in their shots.
The CDC is adamant there is no risk.
"The preponderance of evidence consistently does not reveal an association
between thimerosal (mercury) and autism," Julie Gerberding, the CDC's
director, said at a recent news conference.
But The Star's examination found that:
.. Lower prices appear to be a major factor in the continuing use of flu
vaccines that contain mercury - yet mercury-free vaccines cost only about
$2.50 a dose more.
.. The small amount of mercury in flu vaccine still exceeds the U.S.
Environmental Protection Agency's daily safety threshold, even though the
cumulative amount children now receive from all vaccines is much lower than
it was in 1999.
.. A massive government database that could be used to study the safety of
flu vaccines and other vaccines containing mercury has been kept off-limits
to some researchers, a move that an independent advisory body has
.. At least six states have restricted the amount of mercury allowed in
vaccines. A dozen others are considering it, and a similar bill is pending
in Congress. Many European countries and Japan already restrict mercury in
Pharmaceutical companies, however, insist that flu vaccines containing
mercury are safe.
Chiron Corp., for example, is making 18 million to 26 million doses of
vaccine this season for people ages 4 and older. Most of the doses contain
"There have been a number of studies that have not found a link" to autism,
said Alison Marquiss, a Chiron spokeswoman. "But at the same time, we're
following government guidelines. It's been an ongoing discussion between
government and industry, and everybody is working toward the same goal of
If mercury is a health concern, why is it still in some childhood flu
vaccines? The reason government officials cite most is money.
Mercury-free vaccine must be made in single-dose packages, which is more
expensive than making multidose vials.
Sue Denny, a spokeswoman for the Missouri Department of Health and Senior
Services, said the CDC's cost per dose for a 10-dose vial of flu vaccine is
$9.71. A single-dose package costs the CDC $12.02.
"So if you're buying a lot if it, it makes a difference," Denny said.
The flu vaccines in question contain thimerosal, a compound that is 49.6
percent mercury by weight. Thimerosal has been used for decades in other
vaccines and medical products as a preservative and to prevent contamination
from multiple needle punctures into the vials.
But in the 1990s, health officials increased the number of recommended
childhood vaccines. That meant many babies went from getting 25 micrograms
of mercury in one day to up to 62.5 micrograms in one day.
After it was found that infants were receiving amounts of mercury above the
limits considered safe by the Environmental Protection Agency, government
and private health agencies in 1999 recommended removing mercury from such
childhood vaccines as hepatitis B, DTP and Hib.
The CDC says that because mercury has been removed from all other childhood
vaccines, it is not a problem that it remains in flu vaccines because the
cumulative exposure now is much lower.
But the flu shot given many babies today contains 12.5 micrograms of
mercury -- 14 times the daily amount considered safe by the EPA for a child
weighing 20 pounds. Young children routinely are given a second
12.5-microgram dose a month later.
Other health agencies have limits for mercury exposure, but the EPA's are
considered "a scientifically justifiable level for the protection of human
health" by the National Academy of Sciences.
CDC officials said that because the EPA's guidelines cover an extended
period and not a one-time flu shot, it is unfair to assume the vaccine could
Still, Richard Deth, an expert on drugs that affect the brain, said that "it
does make a difference when it's all given in one day." Deth said his
studies at Northeastern University in Boston have found that even low
concentrations of thimerosal can hurt the development of brain cells.
"The one time is important because the driving force for going into the
brain is the concentration at any one time," Deth said. "So when you get a
(large) dose like that, it more or less drives it into the brain based on
that higher, even temporary, concentration."
Some lawmakers are concerned that government and industry are not moving
quickly enough to remove mercury from all vaccines.
"The fact is there should not be any mercury in any vaccine," said U.S. Rep.
Dan Burton, an Indiana Republican who led a congressional committee that
researched the issue for several years. Burton has a grandson who is
But a professor of pediatrics at the University of Missouri-Columbia said
her research has found nothing to link mercury in vaccines with autism.
"Obviously, it's worrisome to families, and it seems reasonable to conclude
that a relationship exists," said Judith Miles, the director of MU's medical
"However, if you look at the data, there is simply no relationship between