Don’t be scared: Let’s see what’s really in vaccines 


Let’s talk about vaccine ingredients. I am reading less about vaccines causing autism (we all know that theory is utter nonsense, right?) and more about vague concerns regarding the chemicals in vaccines. To begin with, we are surrounded by chemicals. Water (H2O), caffeine (C8H10N4O2), sugar (C12H22O11) are all chemicals.  But perhaps it is the unfamiliar ingredients that people find intimidating.

Let’s tackle the ingredients in the measles, mumps, rubella and varicella (MMRV) vaccine and see what there is to fear:

Sucrose, hydrolyzed gelatin, sorbitol, monosodium L-glutamate, sodium phosphate, albumin, sodium bicarbonate, potassium phosphate monobasic, potassium chloride, potassium phosphate dibasic, neomycin, bovine calf serum, chick embryo cell culture, WI-38 human diploid lung fibroblasts, and MRC-5 cells.

That is 15 ingredients in one 0.5 mL injection. Grab a cup of C8H10N4O2 because we are going to cover each one. The last four, bovine calf serum, chick embryo cell culture, WI-38 human diploid lung fibroblasts, and MRC-5 cells, are the ingredients used to make the attenuated live viruses used in the vaccine.  They also sound the most foreign, so I will start there.

A virus is a parasitic microorganism. It has to invade a cell and use the cell’s resources to survive and replicate. In order to make viruses for use in vaccines, scientists must first grow cells to host the virus. Bovine calf serum is used to provide nutrients to the cells. The types of cells used are named in the list of ingredients. Chick embryo cells are able to grow measles and mumps. A human cell line of fibroblasts (a fibroblast is a type of cell) called WI-38 grows rubella virus. A second human cell line called MRC-5 grows varicella.

Making these viruses attenuated, or weak, and suitable for vaccines involves gradually decreasing the temperature the cells are grown in over generations of viral replication. Normal measles virus prefers to replicate at human body temperature. With the decrease in temperature, the laboratory virus population adapts. Subsequent generations become proficient at replicating at 83 to 93 degrees Fahrenheit (instead of 98.6 degrees). When this weakened virus is injected into your body and subjected to normal body temperature, it is sluggish and slow, and your immune system can kill it off before it is able to establish infection.

When the generations of attenuated virus have developed, the infected cells are put in a centrifuge. This machine rapidly spins the cells, rupturing the walls and allowing the virus to separate away from the other cell contents. The virus is then available to be placed in the vaccine. The cells and the serum that helped grow them are listed as ingredients, but in reality there is only a possibility of trace remnants present in the actual vaccine.

Neomycin is an antibiotic to keep bacteria from contaminating the vaccine. Neomycin is the same antibiotic present in Neosporin and triple antibiotic ointment. There are five micrograms in the vaccine injection. This is approximately 1/500th of the amount of neomycin present in the amount of Neosporin that you would apply to a small cut.

The rest of the ingredients are used to maintain the pH and the stability of the virus so that it is still alive and potent enough to allow you to develop immunity when you get your shot.

Sucrose is table sugar. 20 milligrams of sugar, or 1/200th of a teaspoon, are present in the vaccine.

Sodium bicarbonate is baking soda.

Hydrolyzed gelatin can also be found in Jello.

Sorbitol is also used as an artificial sweetener in chewing gum and Vitamin C tablets.  Your body makes sorbitol during the sugar break-down process.

Monosodium glutamate, a.k.a. MSG, is an amino acid known for giving umami flavor to many Chinese dishes. It is also found in mushrooms and breast milk. There is more MSG in a fresh tomato than there is in the MMRV vaccine.

Albumin is a protein. In fact, it is the most abundant protein in your blood plasma. Every day your liver makes about 40,000 times more albumin than the amount present in the MMRV vaccine.

The rest of the ingredients: sodium, potassium, phosphate and chloride are electrolytes that your body uses every day.

To sum up, we have three kinds of cells that are not actually present in the vaccine. Cell food, which is also not in the vaccine. An antibiotic to keep the vaccine free of bacteria. Two ingredients that your body makes naturally. Four ingredients that are in my kitchen cupboard right now, except in vastly greater quantities. And electrolytes that our bodies take in and use and excrete on a daily basis. I do not think these chemicals sound scary.

In fact, I think the chemicals that we use to prevent people from dying of dehydration, respiratory distress and bacterial superinfections (all of which can happen as a result of measles infection) are more complex and bring with them more potential for side effects than any of the chemicals found in the MMRV vaccine.

Katie Noorbakhsh is a pediatric emergency physician who blogs at Dr. Katie.  She can be reached on Twitter @mamakatemd.


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