A 1998 study suggested the measles/mumps/rubella vaccine might cause autism. Although the study was found to be fraudulent, the public became very concerned with vaccine ingredients.
All vaccines contain antigens, which are the active ingredients that prompt the body to form immune cells that will protect against a future infection. Antigens can be weakened, live viruses; inactivated, killed viruses; or partial viruses or bacteria. Weakened viruses do not reproduce well enough in the body to cause disease but still prompt an immune response. Inactivated or partial viruses or bacteria cannot reproduce but still stimulate immune cells.
What else do vaccines contain?
- Preservatives in vaccines originally were used to prevent germ contamination. With changes in technology, the need for vaccine preservatives has decreased significantly. Until 2001, thimerosal commonly was used in vaccine manufacturing, but few vaccines contain it today. There have been very few serious adverse events associated with the use of preservatives.
- Adjuvants enhance the immune response. Aluminum salts are a common adjuvant. Aluminum is abundant in our environment and is found in food, water, infant formula and breast milk. The amount used in vaccines is similar to that found in 33 ounces of infant formula. Aluminum in vaccines has a 75-year safety record. Serious adverse effects to aluminum adjuvants are rare, but local reactions such as redness, swelling and tenderness at the injection site are not infrequent.
- Stabilizers protect vaccines from heat, light, acidity or humidity. Examples are gelatin, phenols, albumin, sucrose, MSG, lactose and glycine.
- Formaldehyde is used to kill germs that might cause contamination during production. Although most of it is purified away, small residuals remain. Formaldehyde is produced naturally in the human body and is 10 times greater in blood than in any vaccine. Studies have shown that the amount of formaldehyde naturally found in the blood of a newborn of average weight is 50 to 70 times higher than the amount in multiple vaccines.
- Antibiotics are used in the production of some vaccines to prevent contamination from bacteria. The kind of antibiotics used rarely cause allergic reactions.
- Although mostly removed, trace amounts of substances used in the early stages of vaccine production remain. Examples are egg or yeast protein.
Vaccines are extensively tested and highly regulated products. In fact, we are exposed to much higher levels of chemicals in our everyday lives in the environment, our food and water.
In January, the Institute of Medicine convened a special committee to conduct an independent evaluation of studying the safety of the childhood immunization schedule. No evidence of major safety concerns was found.
Janice Poirot is a public health nurse with the Northwest Colorado Visiting Nurse Association.
If you have concerns about vaccine safety, talk to your doctor or visit these online resources.