Why do some vaccines contain preservatives?
Preservatives are included in some vaccines to prevent vaccines from becoming contaminated by bacteria. One preservative contained in some vaccines is called thimerosal. Thimerosal contains mercury. Recent studies by the National Institutes of Health showed that the levels of mercury in the blood of immunized children are similar to those of unimmunized children. But the Centers for Disease Control and Prevention have recommended that thimerosal be removed from vaccines. All routinely recommended vaccines should be free of thimerosal as of Spring of 2001. From National Network for Immunization Information, 2000.
