Remember when we all thought mercury was bad for us?
Vaccines in the United States have historically contained a compound called thimerosal, which includes ethylmercury, as a preservative. Here's a detailed breakdown:
- Thimerosal: This preservative was used in multi-dose vials of vaccines to prevent bacterial and fungal contamination. Thimerosal contains ethylmercury, which is different from methylmercury, the type of mercury found in certain fish that can accumulate in the body.
- Current Status:
- Routine Childhood Vaccines: Most routine childhood vaccines, like the MMR (measles, mumps, rubella), varicella (chickenpox), inactivated polio, and others, do not contain thimerosal. Since 2001, thimerosal has been removed from or reduced to trace amounts in all vaccines routinely recommended for children 6 years of age and younger, except for some influenza vaccines.
- Influenza Vaccines: Some multi-dose vials of flu vaccines still contain thimerosal as a preservative. However, there are also thimerosal-free versions of the flu vaccine available, often in single-dose vials or syringes.
- Trace Amounts: Even in vaccines where thimerosal has been removed, trace amounts of mercury might still be present, but these are significantly below levels considered harmful.
- Global Use: The use of thimerosal in vaccines varies globally. In some countries, thimerosal might still be used in certain vaccines due to different manufacturing practices or because of the need for multi-dose vials in resource-limited settings.
The concern over mercury in vaccines largely stems from misunderstandings or misinformation about ethylmercury versus methylmercury. Ethylmercury is metabolized and cleared from the body much more quickly than methylmercury. Multiple studies and health organizations, including the CDC, WHO, and FDA, have concluded that the presence of thimerosal in vaccines does not lead to health issues like autism or neurological damage.
If you're concerned about mercury in vaccines, you can discuss options with your healthcare provider, as there are thimerosal-free alternatives available for many vaccines.