Is Aluminum the New Thimerosal?
By Robert W. Sears Issue 146, January/February 2008

Vaccines have become the most controversial
parenting topic of the decade. When parents are
considering whether or not to vaccinate their
children, one of the things that must be considered is aluminum toxicity.

Aluminum is added to a number of vaccines to help
them work better. Normally, one wouldn't consider
aluminum to be a problem. It's a naturally
occurring element that is present everywhere in
our environment—in food, water, air, and soil.
It's also a main ingredient in over-the-counter
antacids. And because the body doesn't absorb
aluminum, it's harmless when swallowed.

I didn't think much about aluminum when, 13 years
ago, I began researching vaccines. In fact, the
early seminars on vaccine education that I
offered to parents included a brief statement
that aluminum was nothing to worry about. But as
I read each product insert and saw the number of
micrograms (mcg) of aluminum contained in several
vaccines, I wondered, "Has anyone determined what
a safe level of injected aluminum actually is?" I
didn't have to wonder for long, because the
answer is easy to find; go to, search
on "aluminum toxicity," and you'll find several documents about aluminum.

The first document I came across discusses the
labeling of aluminum content in injected dextrose
solutions (the sugar solutions added to
intravenous fluids in hospitals): "Aluminum may
reach toxic levels with prolonged parenteral
administration [i.e., injected into the body] if
kidney function is impaired. . . . Research
indicates that patients with impaired kidney
function, including premature neonates [i.e.,
babies], who received parenteral levels of
aluminum at greater than 4 to 5 micrograms per
kilogram of body weight per day, accumulate
aluminum at levels associated with central
nervous system and bone toxicity. Tissue loading
[i.e., toxic buildup in certain body tissues] may
occur at even lower rates of administration.

For a tiny newborn, this toxic dose would be 10
to 20 mcg; for an adult, it would be about 350 mcg.

The second document discusses aluminum content in
IV feeding solutions, or Total Parenteral
Nutrition (TPN) solutions. The FDA requires these
solutions to contain no more than 25 mcg of
aluminum per liter of solution. A typical adult
in the hospital would get around 1 liter of TPN
each day, thus about 25 mcg of aluminum. The FDA
document also states, "Aluminum content in
parenteral drug products could result in a toxic
accumulation of aluminum in individuals receiving
TPN therapy. Research indicates that neonates and
patient populations with impaired kidney function
may be at high risk of exposure to unsafe amounts
of aluminum. Studies show that aluminum may
accumulate in the bone, urine, and plasma of
infants receiving TPN. Many drug products used
routinely in parenteral therapy may contain
levels of aluminum sufficiently high to cause
clinical manifestations [i.e., symptoms]. . .
Aluminum toxicity is difficult to identify in
infants because few reliable techniques are
available to evaluate bone metabolism in
premature infants. . . Although aluminum toxicity
is not commonly detected clinically, it can be
serious in selected patient populations, such as
neonates, and may be more common than is recognized."2

Elsewhere, I found a relevant 2004 statement by
the American Society for Parenteral and Enteral
Nutrition (ASPEN), a group that monitors oral and
injectable nutritional products for safety and
side effects. It reiterated the cited FDA
warnings to the letter, and recommended that
doctors purchase IV products with the lowest
aluminum content possible, "and should monitor
changes in the pharmaceutical market that may affect aluminum concentrations."3

The source of the daily limit of 4 to 5 mcg of
aluminum per kilogram of body weight quoted by
the ASPEN statement seems to be a study that
compared the neurologic development of about 100
premature babies who were fed a standard IV
solution that contained aluminum, with the
development of 100 premature babies who were fed
the same solution with almost all aluminum
filtered out. The study was prompted by a number
of established facts: that injected aluminum can
build up to toxic levels in the bloodstream,
bones, and brain; that preemies have decreased
kidney function and thus a higher risk of
toxicity; that an autopsy performed on one
preemie whose sudden death was otherwise
unexplained revealed high aluminum concentrations
in the brain; and that aluminum toxicity can
cause progressive dementia. The infants who were
given IV solutions containing aluminum showed
impaired neurologic and mental development at 18
months, compared to the babies who were fed much
lower amounts of aluminum. Those who got aluminum
received an average of 500 mcg of the metal over
a period of 10 days, or about 50 mcg per day. The
other group received only about 10 mcg of
aluminum daily—4 to 5 mcg per kilogram of body
weight per day.4 This seems to be the source of this safety level.

However, none of these documents or studies
mentions vaccines; they look only at IV solutions
and injectable medications. Nor does the FDA
require labels on vaccines warning about the
dangers of aluminum toxicity, although such
labels are required for all other injectable medications.

All of these studies and label warnings seem to
apply mainly to premature babies and kidney
patients. What about larger, full-term babies
with healthy kidneys? Using the 5 mcg/kg/day
criterion from the first document as a minimum
amount we know a healthy baby could handle, a
12-pound, two-month-old baby could safely receive
at least 30 mcg of aluminum per day. A 22-pound
one-year-old could receive at least 50 mcg
safely. Babies with healthy kidneys could
probably handle much more than this, but we at
least know that they can handle this much.
However, these documents don't tell us what the
maximum safe dose would be for a healthy baby or
child, and I can't find such information
anywhere. This is probably why the ASPEN group
suggests, and the FDA requires, that all
injectable solutions be limited to 25 mcg; we at
least know that that level is safe.

Calculating Aluminum in Vaccines
Here are the current levels of aluminum per shot
of the following vaccines, as listed on each vaccine's packaging:

* DTaP (for Diphtheria, Tetanus, and
Pertussis): 170–625 mcg, depending on manufacturer
* Hepatitis A: 250 mcg
* Hepatitis B: 250 mcg
* HIB (for meningitis; PedVaxHib brand only): 225 mcg
* HPV: 225 mcg
* Pediarix (DTaP–Hepatitis B–Polio combination): 850 mcg
* Pentacel (DTaP–HIB–Polio combination): 1500 mcg
* Pneumococcus: 125 mcg

In other words, a newborn who gets a Hepatitis B
injection on day one of life would receive 250
mcg of aluminum. This would be repeated at one
month with the next Hep B shot. When, at two
months, a baby gets its first big round of shots,
the total dose of aluminum could vary from 295
mcg (if a non-aluminum HIB and the
lowest-aluminum brand of DTaP are used) to a
whopping 1225 mcg (if the Hep B vaccine is given
along with the brands with the highest aluminum
contents). If the Pentacel combo vaccine is given
along with the Hep B and Pneumococcus vaccines,
the total aluminum dose could be as high as 1875
mcg. These doses are repeated at four and six
months. With most subsequent rounds of shots, a
child would continue to get some aluminum
throughout the first two years. But the FDA
recommends that premature babies, and anyone with
impaired kidney function, receive no more than 10
to 25 mcg of injected aluminum at any one time.

As a medical doctor, my first instinct was to
worry that these aluminum levels far exceed what
may be safe for babies. My second instinct was to
assume that the issue had been properly
researched, and that studies had been done on
healthy infants to determine their ability to
rapidly excrete aluminum. My third instinct was
to search for these studies. So far, I have found
none. It's likely the FDA thinks that the kidneys
of healthy infants work well enough to excrete
aluminum before it can circulate through the
body, accumulate in the brain, and cause toxic
effects. However, I can find no references in FDA
documents that show that using aluminum in
vaccines has been tested and found to be safe.

So I did what any pediatrician would do. I turned
to the American Academy of Pediatrics (AAP), who
in 1996 published a policy statement, "Aluminum
Toxicity in Infants and Children," that made the following points:

* Aluminum can cause neurologic harm.
* A study from 30 years ago showed that
human adults increase their urine excretion of
aluminum when exposed to higher levels of the
metal, which suggests that adults can clear out excess aluminum.
* Adults taking aluminum-containing antacids
don't build up high levels of aluminum in their bodies.
* Reports of infants with healthy kidneys
show elevated blood levels of aluminum from taking antacids.
* People with kidney disease who build up
bloodstream levels of aluminum greater than 100
mcg per liter are at risk of toxicity.
* The toxic threshold of aluminum in the
bloodstream may be lower than 100 mcg per liter.
* The buildup of aluminum in tissues has
been seen even in patients with healthy kidneys
who receive IV solutions containing aluminum over extended periods.5

However, nowhere in this paper was there any mention of aluminum in vaccines.

To put this in perspective: Because the body of
the average adult contains about 5 liters of
blood, receiving more than 500 mcg of aluminum in
the bloodstream all at once will be toxic if the
kidneys aren't working well. (Toxicity has also
been seen in patients with healthy kidneys.)
Because a newborn's body contains about a liter
(300 milliliters) of blood, more than 30 mcg of
aluminum floating around in the bloodstream could
be toxic if the baby's kidneys aren't working
well. The body of a toddler or preschool-age
child contains about 1 liter of blood, so more
than 100 mcg in his system could be toxic—and, as
we've seen, babies can receive more than 1000 mcg
of injected aluminum all at one time.
Fortunately, this amount doesn't all go into the
blood at once, but is slowly diffused into the
bloodstream over a period of time from the muscle
or skin where it was injected.

But that is the main point of this article. No
one has measured the levels of aluminum
absorption by the bloodstream when it is injected
into the skin and muscle of infants, or the
levels of excretion from the body via urination.
All of the FDA and AAP documents that I've read
state that aluminum might be a problem, but that
they haven't studied it yet, so we should limit
the amount of aluminum included in injectable
solutions. But, again, no one is talking about
the levels of aluminum in vaccines.

What I think may have happened is that because
aluminum used to be found in only one
vaccine—DTP, an older version of the current DTaP
vaccine—no one thought much about it. Then, in
the 1980s, the PedVaxHib brand of HIB meningitis
vaccine was released, which also included
aluminum; but other brands of HIB vaccine did
not, so again, no one thought much about it. In
the 1990s, the Hepatitis B vaccine began to be
widely used; in the 2000s, the Pneumococcus
vaccine; and, more recently, the Hepatitis A
vaccine. Administering one aluminum-containing
vaccine at a time involves only a small amount of
the metal; administering four such vaccines
simultaneously is a different story. It seems
this issue has simply escaped everyone's attention. Or has it?

Limited Studies limit thinking
Several years ago, some suspected cases of
aluminum toxicity resulted in various neurologic
and degenerative problems. The Cochrane
Collaboration, a group that studies health-care
issues around the world, wanted to look at a very
large study group to see if there was a real
correlation between neurologic problems and the
aluminum in vaccines. They investigated all the
reported side effects of one aluminum-containing
vaccine, DTP (no longer used), and looked for any
evidence that such vaccines caused more side
effects than non-aluminum vaccines. Other than
more redness, swelling, and pain at the injection
site, they found no indication that an
aluminum-containing vaccine caused any more
problems, and concluded that no further research
should be undertaken on this topic.6 That is a
very bold statement. Most researchers will draw
conclusions from the findings of their own
research; it's unusual to say that no one else
should do any more research into the matter.

This is especially surprising because of the
limitations of the Cochrane Collaboration's
study. They looked at the effects of only one
standard aluminum-containing vaccine, rather than
the effects of all four being administered at
once. They didn't study aluminum metabolism
itself. They didn't test aluminum levels in
children after vaccination, nor did they explore
whether or not the amount of aluminum in vaccines
builds up in the brain or bone tissues. They
looked only for evidence of external symptoms of
aluminum toxicity, not internal effects. Nor did
they do their own research; instead, they
reviewed all available studies conducted by other
investigators. Despite all this, the Cochrane
Collaboration study essentially closed the book
on investigating aluminum toxicity from vaccines,
without really having opened it in the first place.

The most obvious way to study this matter would
be to inject various amounts of aluminum into
children and see what happens to them internally.
We know from the FDA documents that aluminum
toxicity does occur from other types of
injectable treatments; that it accumulates in the
brain and bones in toxic amounts; that this may
occur more commonly than is recognized; and that
aluminum toxicity is hard to detect by looking
for external symptoms. The question remains: What
happens when these amounts of aluminum are
injected via vaccines? Vaccine manufacturers may
have begun to wonder about the same thing; I
found some interesting research in the product
insert of the new HPV vaccine, Gardasil. In
researching the safety of Gardasil, Merck & Co.,
Inc., the vaccine's developer and manufacturer,
added a step to their testing procedure by
injecting aluminum into a separate group of test
subjects used as a safety control group. They
then compared the side effects of the Gardasil
vaccine with a saline placebo that contained
neither Gardasil nor aluminum, as well as with
the placebo containing no Gardasil but the same
amount of aluminum as the vaccine. They found
that the placebo containing aluminum was much
more painful than the saline placebo, and about
as painful as the full HPV shot. The aluminum
placebo also caused much more redness, swelling,
and itching than the saline placebo, though not
quite as much as the full HPV shot.

Unfortunately, Merck looked only at the effects
of aluminum at the injection site. Nor did they
state in the Gardasil product insert what role
the aluminum placebo played in all the other
standard side effects, such as fever and flu-like
symptoms. Nor did they study the body's internal
metabolism of aluminum. However, their research
did show how irritating aluminum can be when
injected into the muscles. It was a good first
step. If aluminum can be toxic, why not just
remove it from vaccines, as is being done with
the preservative thimerosal, which contains the
neurotoxin mercury? It's not that simple.
Aluminum is an adjuvant; in other words, it helps
vaccines work more effectively. When the metal is
mixed with a vaccine, the body's immune system
more easily recognizes the vaccine and creates
antibodies against the disease. Thimerosal was
easy to omit, because it has nothing to do with
the efficacy of the vaccine itself. But the
pharmaceutical companies would need good evidence
that aluminum is harmful before they would invest
in coming up with new, aluminum-free vaccines.
(The Cochrane Collaboration report pointed out
that removing aluminum from vaccines would then
require extensive trials of the reformulated vaccines.7)

What, exactly, does a toxic level of aluminum do
to the brain? While no one has studied healthy
babies to see how much, if any, aluminum builds
up in the brain from the amounts of aluminum used
in vaccines, the study on IV feeding solutions in
premature babies mentioned above revealed that
aluminum impaired their neurologic and mental
development.8 But that was in premature babies,
not healthy, full-term infants. I found several
animal studies involving aluminum and/or
aluminum-containing vaccines that did show
neurologic harm. Not only did aluminum build up
in the brain and cause damage, but some of the
damage looked similar to what is seen in the
brains of Alzheimer's patients.9-1314 However,
it's hard to draw conclusions about aluminum's
effects on humans from studies of animals. What
we need are more studies of human infants.

A Call for Better Research
There is good evidence that large amounts of
aluminum are harmful to humans. Because no
meaningful research has specifically been done on
aluminum in vaccines, there is no existing
evidence that the amount in vaccines is harmful
to infants and children. However, no one has
actually studied aluminum levels in healthy human
infants after vaccination to make sure it is
safe. Should we now stop and research this
matter? Or should we just go on, continuing to
hope that it is safe to use aluminum as an adjuvant in vaccines?

Vaccine policy makers and advocates may read this
article, review my perspective, and initiate
research studies to explore the risks of
aluminum. I would hope that those researchers do
not conduct a retrospective review of all the old
vaccine safety studies and journal articles to
look for the side effects of aluminum. As the
FDA, AAP, and others have stated, aluminum
toxicity can't be detected by external
observation alone. It would be a waste of time,
and a grave disservice to the health of America's
children, to have several such reports show up in
the medical literature. The only way the issue of
aluminum safety can be put to rest is to conduct
real-time studies on thousands of infants and
measure aluminum levels after vaccination.

In such a study, the researchers should look not
only at blood levels. They should also find out
whether or not aluminum accumulates in the body,
where it accumulates, how the body eliminates it,
and at what rate. Once I see such research, and
have determined to my satisfaction that aluminum
has been proven safe, I will post an update on, and revise future
editions of the book accordingly. If such
research finds that aluminum may not be safe,
then I would expect a new vaccine schedule to be
adopted in which the administering of vaccines is
spread out to minimize the amount of aluminum a
child receives at any given time. I would also
expect vaccine manufacturers to begin finding
ways to reduce or remove aluminum from vaccines
without compromising their effectiveness. We need
to know the answers to many questions: Why does
one brand of HIB vaccine require aluminum to make
it work while another brand does not? Why does
one brand of DTaP vaccine contain four times as
much aluminum as another? Why does one brand of
combination vaccine contain three times as much
aluminum as the sum of its parts?

Learning from the Past
I worry that aluminum may end up being another
thimerosal. I am relieved that, as of 2002, the
mercury-containing preservative had been removed
from most vaccines. But according to an article
in the Los Angeles Times, Merck & Co., the makers
of several vaccines, knew in 1991 that the
cumulative amount of mercury in vaccines given to
infants by six months of age was about 87 times
the level then thought to be safe.14 The article
includes a copy of an internal memo, written by
one of Merck's research doctors and sent to the
president of Merck's vaccine division, clearly
stating the doctor's worry about mercury
overload. What was done with that information
back in 1991? We'll never know. What we do know
is that vaccine manufacturers knew that we were
overdosing babies, but that the mercury wasn't
removed from vaccines until 10 years later. This
was because few paid attention to the potential
problems with mercury. When we did find out, we
hoped it wasn't harmful, we did extensive
research to try to show that it wasn't, and we
slowly removed it from most vaccines.

The issue of mercury toxicity from vaccines is
moot for infants receiving vaccines today, as
long as doctors and parents choose a flu shot
without mercury, know which brands of vaccines
still contain barely detectable traces of
mercury, and are aware that some plain Tetanus
and Diphtheria-Tetanus vaccines still contain
mercury (though these last vaccines are not parts
of the routine vaccine schedule). [For a current
list of vaccines and their thimerosal contents,
go to www.vaccine—Ed.]

What isn't moot is the question of aluminum
toxicity. As doctors, we can choose certain
vaccine brands that contain less or no aluminum.
We can be careful about giving only one
aluminum-containing vaccine at a time. And we can
talk about it instead of sweeping the issue under
the rug. I pray that my fears about aluminum are
unfounded, and that objective studies performed
by completely independent groups with no ties to
vaccine manufacturers or political organizations
show that it is safe. If not, I would hope that
manufacturers would start to reduce or eliminate
the aluminum content of their vaccines as soon as
possible. I know this won't be an easy task, but our children are worth it.

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