Excipients in vaccines are chemicals that are not the main active ingredient, but are added to vaccines for several purposes. Preservatives are added to prevent contamination, and adjuvants are added to “killed virus” or subunit vaccines, and are designed to make the antigens more reactive and have a longer duration of action. This seems to be a good idea, but unfortunately there is a bad side, particularly to the two most popular additives: thimerosal and aluminum. Thimerosal, a preservative, is a mercury compound, added to vaccines to kill any “live viruses,” fungi, and bacteria in the vial. Aluminum (as aluminum hydroxide or aluminum phosphate) is an adjuvant in vaccines meant to boost antibody response. Both of these metals are regarded as environmental toxins.
