Common substances found in vaccines include:
- Aluminum gels or salts
of aluminum which are added as adjuvants to help the vaccine stimulate a
better response. Adjuvants help promote an earlier, more potent
response, and more persistent immune response to the vaccine.
See also: "Aluminum in Vaccines: What you should know [2 pages]" Also available in Spanish [2 pages]
- Antibiotics which are added to some vaccines to prevent the growth of germs (bacteria) during production and storage of the vaccine. No vaccine produced in the United States contains penicillin.
- Egg protein is found in influenza and yellow fever vaccines, which are prepared using chicken eggs. Ordinarily, persons who are able to eat eggs or egg products safely can receive these vaccines.
- Formaldehyde is used to inactivate bacterial products for toxoid vaccines, (these are vaccines that use an inactive bacterial toxin to produce immunity.) It is also used to kill unwanted viruses and bacteria that might contaminate the vaccine during production. Most formaldehyde is removed from the vaccine before it is packaged.
- Monosodium glutamate (MSG) and 2-phenoxy-ethanol which are used as stabilizers in a few vaccines to help the vaccine remain unchanged when the vaccine is exposed to heat, light, acidity, or humidity.
- Thimerosal is a mercury-containing preservative that is added to vials of vaccine that contain more than one dose to prevent contamination and growth of potentially harmful bacteria.
What You Can Do
- To find out what chemical additives are in specific vaccines, ask your healthcare provider or pharmacist for a copy of the vaccine package insert, which lists all ingredients in the vaccine and discusses any known adverse reactions.
- To ensure the safety of vaccines, the Centers for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA), the National Institutes of Health (NIH), and other Federal agencies routinely monitor and conduct research to examine any new evidence that would suggest possible problems with the safety of vaccines. To keep abreast of the latest information, continue to reference these materials.
- To report a health problem that followed vaccination you or your provider should call the Vaccine Adverse Event Reporting System (VAERS) at 1-800-822-7967.
For More Information
- CDC-INFO Contact Center:
English and Spanish
- Journal article:
PEDIATRICS December 2003
Addressing Parents' Concerns: Do Vaccines Contain Harmful Preservatives, Adjuvants, Additives, or Residuals?
Source: Pediatrics Vol. 112 No. 6 December 2003, pp. 1394-1397
...quantities of mercury, aluminum, formaldehyde, human serum albumin, antibiotics, and yeast proteins in vaccines have not been found to be harmful in humans or experimental animals...
If someone told you they were going to be be injecting heavy metals, emulsifiers, preservatives and synthetic additives (like peanut oil and chicken embryo) into your muscle tissue? Would you let them? What about MSG and formaldehyde? What about aluminum and mercury?