February 11 – Beware of DHMO!

Today’s factismal: The average vaccine includes about eight ingredients.

If you are ever looking for something to scare the pants off of someone, point out the many dangers of dihydrogen monoxide. If you believe the hype, it is one of the most dangerous chemicals around and kills at least ten people each day. But if you know the science then you know that dihydrogen monoxide is just another way of saying “water” and that its benefits far outweigh the risks.

The same is true of vaccines. If you look at the CDC’s list of ingredients in vaccines and don’t know the chemistry and biology, then it can be pretty scary. There are about 200 ingredients given for the 53 vaccines listed and many of them have names like D-fructose and phenol. But once you know what the ingredients are for (and what levels there are of them), then you realize that the folks telling you that vaccines have “poison” in them are about as truthful as the folks who claim that dihydrogen monoxide is a deadly killer.

The number of ingredients in vaccines (Data courtesy CDC)

The number of ingredients in vaccines
(Data courtesy CDC)

In general, the ingredients in a vaccine are there for one of five reasons: they cause your immune system to develop an immunity, they stimulate your immune system, they feed or nurture the stuff in the vaccine, they keep other viruses and bacteria from growing in the vaccine, or they make the vaccine easier to use. Let’s look at each of these categories in turn.

First, the stuff that causes your immune system to develop an immunity; when listed, it is given names like MRC-5 cellular proteins or insect cell, bacterial, and viral protein. Generally, this is the virus itself usually present in a weakened form (“live vaccines”) or as a protein fragment (“killed vaccines”). When exposed to these viruses in a controlled way, your immune system develops a specific set of antibodies that will attack that virus the next time it is seen. This the basis of Jenner’s vaccinations against smallpox back in 1796. Indeed, that’s what gave us the word “vaccinate”; because Jenner used cowpox to prevent smallpox, the word for the procedure was “born from a cow” or “vacca (cow) innatus (born in)”. Without these bits of the virus, the vaccine would be nothing but a shot of water with trace bits of other stuff.

Next, there’s the stuff to stimulate your immune system. Basically, this stuff is the equivalent of trash-talking before a big fight. Known in medical circles as an adjuvant (“helper”), these chemicals and compounds help make your immune system more sensitive to the active ingredient. So what is in here? Aluminum hydroxide – also known as Gaviscon to you folks with upset stomachs. Dibasic sodium phosphate – which is also used as a leavening agent for bread at the store. And aluminum potassium sulfate – also known as alum or “that stuff that makes pickles so darn sour”.

Third is the stuff that helps the viruses used in the vaccine grow. Most vaccines are grown in what medicos call prosaically enough a “growth medium”. Typical things used for a growth medium include gelatin (just like in Jell-O), agar (just like in toothpaste), and eggs (just like in your breakfast). Basically, if the ingredient name includes “medium”, then it was used to grow the stuff. Though most of this is removed before use, trace amounts always remain. Under US law, those growth media that might cause allergic reactions (such as eggs) or religious problems (such as beef) must be labeled and identified to the patient before use.

Vaccines contain trivial amounts of antiseptics (Data courtesy CDC)

Vaccines contain trivial amounts of antiseptics
(Data courtesy CDC)

Fourth, we’ve got the stuff to keep other viruses and bacteria from growing in the vaccine. The reason for this is obvious; what allows one virus to grow also allows other viruses to grow, along with bacteria and assorted other things that we don’t want. So it is common practice to include antiseptics in the vaccine growth medium and in the vaccine doses to keep them sterile. The most common antiseptic used is formaldehyde, which is found in 28 of the 53 vaccines in the list. Formaldehyde is used because it is very effective as an antiseptic in small doses; typically, there is about 100 micrograms of formaldehyde in a dose of vaccine. For comparison, a typical human has about 6,000 migrograms of naturally-occurring formaldehyde in their blood. Similarly, some vaccines have neomycin (the same stuff found in Neomycin) and a very few have thimerosal (the same stuff found in Merthiolate and many tattoo inks). That last is somewhat controversial due to a now-discredited study (it turns out the guy made up his data {and abused his young patients} so he could make some money) but removing it has increased the costs of vaccines to the point where they are now unaffordable in many third-world countries. As a result, death rates in those countries have increased.

Finally, there is the stuff to make the vaccine easier to use. Most of this is chemicals that keep the bits of dead virus from sticking to each other and forming clumps or that make the vaccine easier to inject. They include potassium chloride (also known as “salt-free table salt”) and potassium phosphate (also known as “the anti-caking agent in soft drink mixes”) and citric acid (also known as “orange juice”) which help to keep the vaccine in the proper pH range and mineral salts (also known as Epsom salts) which help give it the proper salinity. And, of course, every dose of vaccine also has a large dose of dihydrogen monoxide; it is what everything is suspended in.

So that’s what is in a vaccine. A lot of scary sounding stuff that, like dihydrogen monoxide, turns out to be pretty banal once you know what it is and where you’ve seen it before.

3 thoughts on “February 11 – Beware of DHMO!

  1. Pingback: August 1 – Pokey Dokey | Little facts about science

  2. Pingback: May 14 – Controversy | Little facts about science

  3. Pingback: August 1 – A Real Shot In The Arm | Little facts about science

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