In the year 2000, measles was declared “eliminated” in the U.S.
by the Centers for Disease Control. But
this was a short-lived victory for humanity.
As of 2001, measles appears to be making a comeback in
the U.S., as illustrated nicely here by the U.S.
Centers for Disease Control records.
It’s also happening in the UK.
As you may know, this resulted from clusters
of people choosing to forgo the vaccination of their children. Measles is highly contagious and still common
in some parts of the world.
But in the developed world there is obviously some skepticism
brewing regarding the safety of vaccines.
Much of this stems from a bogus study reported in 1998, which linked the
measles-mumps-rubella (MMR) vaccine to autism.
This was discussed in great detail in an article that I previously posted
in this blog.
Here in this article it is my intention to describe – in
layman’s terms – exactly what is in an MMR vaccine. I will focus specifically on the formulation
used in a vaccine called M-M-R II®, which
is manufactured by Merck. Since 1978, over 575 million doses of this particular vaccine have been administered. That makes it
one of the most widely used vaccines for the measles virus, particularly in the U.S.
The full ingredient list for M-M-R II® can be found here. And the precise amount of some of the
ingredients per dose (0.5 milliliters) can be found here,
along with just about anything else you would ever want to know about the
safety of the vaccine according to the U.S. Food and Drug Administration (FDA). The vaccine is supplied as a dehydrated (‘lyophilized’)
powder because it can be easily shipped, stored, and held stable in that state
for longer periods of time. The powder
is re-dissolved into sterile water immediately before the vaccine is administered by injection just below the skin, usually on
the upper arm.
The purpose of any vaccine is to invoke an immune
response to a harmless version of a virus so that you have antibodies to
protect you from the real (harmful) version of the virus for the rest of your
life. In this context, a virus is also
known as an ‘antigen’. A vaccine virus can be made harmless – i.e. ‘attenuated’
– by removing genes or altering its biochemistry in some way that does not
affect your body’s immune response to it.
The M-M-R II® vaccine uses altered versions of the
measles virus, the mumps virus, and the rubella (German measles) virus as
active ingredients.
Because viruses by nature cannot reproduce on their own,
the vaccine viruses would need to be produced by growing a large number of
cells from tissue contained in flasks (in a test-tube, so to speak). The flasks contain a nutrient-rich liquid
called cell culture growth medium. Once
cells are grown, they are then infected with a particular virus and then the
virus will multiply and spread within the cells. The gazillions of new viruses that are then produced
from the infection are extracted and purified from the cells and the liquid
growth medium.
Here is a picture of one of my flasks from the lab, which
contains a red cell culture growth medium.
I am sure Merck uses something a bit more sophisticated to meet their
demands.
Ok, now on to the inactive ingredients.
You may be wondering: Doesn’t the vaccine also contain
CHEMICALS? Yes of course. Everything in the universe is made out of
chemicals, including you. But are they harmful? That is a much better question.
Let’s take a look.
Sorbitol is essentially a type of sugar. Technically, it is also a type of
alcohol. It can be found naturally in
various fruits. It is also produced in the
human body when excess glucose is broken down.
Because it tastes sweet and has a low glycemic index, it is often used in
things like chewing gum and toothpaste. Like most sugars, it can help stabilize
biological material during dehydration and temperature changes. For this purpose it is likely to be included
in the vaccine. Sorbitol can cause
diarrhea if consumed in sufficient doses.
Incidentally, it can be found in some laxatives
as well.
These are salts that work together to maintain pH
stability. Most things in biology,
including the active ingredients in a vaccine, will fall apart if the pH is not
somewhat neutral. A certain pH can be
set and maintained in a liquid by adding these compounds together in a certain
ratio that can be calculated. These
compounds are charged, which means they are ions. Sodium, potassium, and phosphate are also
referred to as electrolytes in the context of physiology. They are common and important parts of every
biological system, and are present in much of what you consume and excrete. Sodium phosphate can be prescribed in large
doses where it acts as a laxative for the
purpose of bowel cleansing prior to a colonoscopy. Different kinds of phosphates are also
commonly used in fertilizers, because plants need them too.
You already know all about this one – it is table
sugar. It is used most often in foods
and beverages to make them taste sweet, as we all know. But its function in a vaccine is the same as
sorbitol (see above). It stabilizes the
active ingredients of the vaccine in their dehydrated state at different
temperatures.
You are also very familiar with this one – table
salt. As with sucrose, its place in a
vaccine has nothing to do with its more familiar culinary use. The correct balance of sodium (Na+) and
chloride (Cl-) ions is important for the stability of any biological compound
in a similar way that pH balance is important.
The active ingredients (i.e. harmless viruses) would likely fall apart
without the proper concentration of sodium chloride.
If the first thing that comes to mind here is Jell-O®, then you are on the right track. Yes, gelatin is
the main ingredient in Jell-O®. But what exactly IS gelatin? Well, it is a protein called collagen that twists around
itself like strings within a rope.
Collagen is what your connective tissue is mostly made out of, and you
have more collagen in your body than any other protein. ‘Hydrolyzed’ means that the long strings of
protein are broken down into smaller fragments by enzymes and heat. In a vaccine, these protein fragments
function in stabilizing the active ingredients.
And all proteins are just a chain of the same various amino acids that
exist in all living things.
Albumin is a common and very abundant protein found in
the blood plasma of animals. Its job is to
maintain the proper balance of water and ions in the bloodstream. When growing the
viruses that are used in the vaccine, this would be an important ingredient to
have in the liquid cell culture growth medium.
Because one dose of the M-M-R II® vaccine has ‘less than or equal to’ 0.3
milligrams of albumin, this may be an indication that its presence is residual,
leftover from the production process after purification. Regardless, it may function as a stabilizer
in the vaccine in a similar way as it does in the bloodstream. This is a human protein, but it does not come
from a human source. The adjective
‘recombinant’ here means that it was produced in another organism (probably
yeast cells) by inserting the corresponding human gene into that organism,
growing it, and extracting and purifying the albumin protein. Because it is so abundant in the blood, it
would certainly be easier to obtain from human blood donors. But apparently Merck went out of their way
here to eliminate that sort of thing from their production process.
This is an extract of a mixture of various compounds
present in the liquid fraction of blood.
And yes, ‘fetal bovine’ indicates that its origin is from cow fetuses,
which may sound alarming. Like albumin,
serum is an important ingredient in the
liquid growth medium that cells are grown in where the vaccine viruses are
being cultivated. For many years,
scientists tried in vain to grow cells from tissues and organs in a test
tube. It wasn't until someone tried adding serum that it finally worked, and it has changed medical research related
to every disease imaginable ever since.
Like the albumin, it is probably only listed as an ingredient in the
vaccine because it may be present in residual amounts after the vaccine viruses are
extracted and purified from where they were grown (1 part per million = 0.0001%). Work is
ongoing to determine which components of serum are important for cell growth so
that they can be produced without needing to source them from animals like
cows.
9. Other
Buffer and Media Ingredients
This is listed here as an ingredient just in case trace amounts
of the compounds from the liquid growth medium that viruses were cultivated in
are still present after purification. Because
as Billy Idol once observed,
“there is nothing pure in this world”.
This is especially true on a molecular level, where 99.999% is about as
pure as anything gets. The culture media
used in the production of the viruses for this vaccine is called Medium 199 and MEM. Included in these media are nutrients that
cells need such as vitamins, amino acids, salts, and glucose.
Neomycin is an antibiotic. It is added to the liquid that the viruses
are cultivated in to prevent bacteria from growing and fouling the sample. Similarly, it is left in or added to the
vaccine to act as a preservative by keeping the vaccine sterile. Neosporin®
is named after neomycin because it is a main active ingredient. It is also in other creams, ointments,
eyedrops, eardrops, and the like. When I
was a child, I learned that I was allergic to the antibiotic penicillin
following treatment of an infection. As
with penicillin and other antibiotics, some people can be allergic to neomycin
– so it is important that it is listed as an ingredient here. A doctor administering a vaccine would be
expected to be aware of this.
There you have it: those are the ten inactive ingredients
in the vaccine for measles, mumps, and rubella that is commonly administered in
the U.S.
The toxicity of these (or any food/drug ingredient) has
more to do with dosage of a substance rather than the substance itself. It is the job of the FDA to regulate safe
amounts of any of these compounds in this vaccine, just as it is their job to
do so with everything else that we consume or use for medicine in the U.S. (with
the exception
of dietary supplements). A thorough evaluation of past scientific
studies on adverse reactions correlated with (but not necessarily caused by)
the use of the M-M-R II® vaccine has been published in peer-reviewed literature
here,
though it should be noted that this literature review was commissioned by
Merck.
To me, it seems that the M-M-R II® vaccine contains a
minimal amount of inactive ingredients in minimal quantities, and it appears
that Merck went out of their way to use ingredients that are already present in
the human body wherever possible – even when cheaper alternatives could be used
without compromising quality.
The ingredients in other vaccines vary, and more
information can be found about them on this useful website put
together by the University of Oxford.
The safety of many other common vaccines has been objectively reviewed
in a very nice recent academic publication that can be found here. And this report has no attachment to a
pharmaceutical company, advocacy group, or any
other potential conflict of interest.