- The proposed global ban on the vaccine preservative thimerosal, urged by U.N., could potentially disadvantage children in economically underprivileged countries by limiting their access to essential vaccines.
- Thimerosal consists of ethyl mercury, a differnt type to methyl mercury which can harm young children’s development. Since the cautionary removal of thimerosal from most vaccines in 1999, research has shown no link between thimerosal and conditions such as autism.
- Developing nations rely on multi-dose vials containing thimerosal, making it an effective and pragmatic option for their vaccination programs. Single dose vials, used in wealthier countries, would pose logistical problems such as increased refrigeration needs.
- The American Academy of Pediatrics (AAP) and World Health Organization (WHO) advocate against the ban, warning it could further lower already low vaccination rates in developing countries.
- A considerable opposition to the AAP and WHO view exists as well, with parties arguing that thimerosal in vaccines is not completely harmless. The U.S. Environmental Protection Agency and Food and Drug Administration still require thimerosal removal from childhood vaccines.
Contrary to a suggestion brought forth by the United Nations to ban the vaccine preservative thimerosal, containing a version of mercury, a prominent association of U.S. pediatricians opposes the move and argues otherwise.
The American Academy of Pediatrics (AAP) aligns with the World Health Organization (WHO) in encouraging the U.N. to abandon the proposal from a global treaty intended to decrease mercury exposure in various ways. Both the WHO and AAP warn that a prohibition on thimerosal could deprive kids in financially disadvantaged countries of essential vaccines.
Opposing the Ban
The AAP, which made its position known to members in June, reasserts its stance and includes three commentaries on the matter.
Thimerosal comprises a type of mercury known as ethyl mercury. It was historically utilized in some vaccines, but in a precautionary move, U.S. health authorities ruled in 1999 that thimerosal be removed from most vaccines administered to young children, with some influenza vaccines being the exception.
This was a preventive measure until researchers could gain a better understanding of the potential influence of the ethyl mercury in thimerosal on the development of children. Ethyl mercury differs from another type of mercury – methyl mercury, which is present in the environment and can adversely impact the evolving brains of young kids.
Current Stand on Ethyl Mercury
Subsequent international investigations have not discovered any detrimental effects, ruling out any link between thimerosal and conditions like autism. As per the U.S. Centers for Disease Control and Prevention, there is a lack of compelling evidence of harm caused by doses of thimerosal in vaccines.
Potential Impacts of the Ban
A global ban on thimerosal could lead to a further decline in the existing low inoculation rates in developing countries, with no potential advantages, warns Dr. Walter Orenstein, a member of the AAP Committee on Infectious Diseases.
Developing nations depend on vaccines that contain thimerosal, Orenstein explains. The preservative is used in vials storing more than one vaccine dose, preventing contamination which can occur when a syringe is introduced into the vial.
Affluent countries like the U.S can bypass the necessity for thimerosal by using single-use vials. However, for poor nations, multi-dose vials are a more pragmatic option for vaccination programs, Orenstein elaborates.
Switching to single-dose vials would present issues, for instance, local clinics would require considerably more refrigeration space to store the same volume of vaccine doses.
“If there’s a ban, we’ll be under-vaccinating them even more” notes Dr. Paul Offit, an infectious disease specialist.
Global Treaties and Responses
The AAP and WHO responses are in reaction to a global treaty being drafted by the UN Environmental Program. This treaty aims to diminish mercury exposure from a range of sources, thimerosal being one of the considerations.
Dr. Michael Smith, a pediatric infectious disease specialist says, “Since 1999, there have been multiple studies that have not found any link between thimerosal and autism.” He agrees with the AAP stance, but adds that the precaution to remove the preservative was made before this information was known.
“To make the same mistake now, with the information we have now, it could result in thousands of deaths.” warns Offit.
Yet, not everyone agrees thimerosal is innocuous. A notable objector includes Barbara Loe Fisher, president of the National Vaccine Information Center.
Furthermore, Fisher expressed concern that current U.S. positions have not shifted. “The Environmental Protection Agency and the Food and Drug Administration have not rescinded the 1999 directive to the pharmaceutical industry to remove thimerosal from childhood vaccines.”
However, regardless of the U.N. treaty outcome, it is unlikely to affect routine childhood vaccinations in the U.S. Though, a global ban on thimerosal could be troublesome in event of an emergency.
For additional details, visit the U.S. Centers for Disease Control and Prevention’s page on thimerosal in vaccines.