Thimerosal was taken out of most childhood vaccines in 2001, only remaining in muti-dose vials of flu vaccines, which could easily be avoided, as a good supply of thimersosal-free flu vaccine has been available for many years.
“Thimerosal is a mercury-based preservative that has been used for decades in the United States in multi-dose vials (vials containing more than one dose) of medicines and vaccines. There is no evidence of harm caused by the low doses of thimerosal in vaccines, except for minor reactions like redness and swelling at the injection site. However, in July 1999, the Public Health Service agencies, the American Academy of Pediatrics, and vaccine manufacturers agreed that thimerosal should be reduced or eliminated in vaccines as a precautionary measure.”
CDC on Thimerosal in Vaccines
For some reason, that hasn’t kept some parents from still being concerned about mercury in vaccines.
Does Pentacel Contain Mercury?
Pentacel is vaccine that combines the diphtheria and tetanus toxoids and acellular pertussis adsorbed, inactivated poliovirus and Haemophilus b conjugate (tetanus toxoid conjugate) vaccines (DTaP-IPV/Hib) into one shot.

It is routinely given to children as a four dose series, when they are 2, 4, 6, and 15 to 18 months old.
Like most other vaccines given to children, Pentacel is thimerosal-free.
It does not contain mercury.
More on Mercury in Vaccines
- VAXOPEDIA – Myths About Thimerosal in Vaccines
- VAXOPEDIA – Thimerosal Hype or Hazard
- VAXOPEDIA – Doing the Math on Kennedy, Vaccines and Mercury
- VAXOPEDIA – Which Vaccines Contain Heavy Metals?
- VAXOPEDIA – Vaccines and the HAZMAT Team Myth
- VAXOPEDIA – How Aluminum Became the New Thimerosal
- CDC – Thimerosal in Vaccines
- FDA – Thimerosal and Vaccines
- CDC – Understanding Thimerosal, Mercury, and Vaccine Safety
- CDC – Frequently Asked Questions about Thimerosal
- FDA – Approved Products > Pentacel
- Is There Mercury in Vaccines?
- Talking about Vaccines: Thimerosal
- Thimerosal | Immunize for Good
- Thimerosal Content in Vaccines
- Thimerosal Content in Some US Licensed Vaccines