Spreeha Choudhury and Richard H. Hughes, IV, attorneys in the Health Care & Life Sciences practice, in the firm’s Washington, DC, office, co-authored an article in Health Affairs, titled “The Lingering Legacy of Thimerosal.”
Following is an excerpt:
When manufacturers and public health officials took steps more than two decades ago to remove thimerosal from most pediatric vaccines, their intention was to bolster public confidence. Instead, it became a double-edged sword, amplifying vaccine misinformation that persists to this day. With Robert F. Kennedy Jr., a prominent vaccine skeptic, now likely to take the role of Secretary of Health and Human Services under a second Trump Administration, thimerosal myths seem to persist no less today.
Thimerosal’s Role in Vaccines
Thimerosal was a key ingredient in early vaccines, introduced as a preservative to prevent bacterial contamination in multi-dose vaccine vials. Its addition not only enhanced vaccine safety by reducing the risk of microbial growth but also allowed for the broader use of multi-dose vials, making vaccination more accessible and cost-effective. Several tragic incidents highlighted the dangers of impure vaccines, prior to the introduction of thimerosal. For example, in 1901, a contaminated diphtheria antitoxin caused the deaths of 13 children in St. Louis, MO, and the same year, improperly produced smallpox vaccines led to additional fatalities in Camden, NJ.
These tragedies prompted Congress to enact the Biologics Control Act of 1902, which marked the first federal oversight of the manufacturing processes for biologic products, including vaccines. This legislation set standards for vaccine safety and paved the way for the eventual creation of the Food and Drug Administration (FDA). Today, the FDA's Center for Biologics Evaluation and Research (CBER) continues to regulate biologics.