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.

Jump to Page

Privacy Preference Center

When you visit any website, it may store or retrieve information on your browser, mostly in the form of cookies. This information might be about you, your preferences or your device and is mostly used to make the site work as you expect it to. The information does not usually directly identify you, but it can give you a more personalized web experience. Because we respect your right to privacy, you can choose not to allow some types of cookies. Click on the different category headings to find out more and change our default settings. However, blocking some types of cookies may impact your experience of the site and the services we are able to offer.

Strictly Necessary Cookies

These cookies are necessary for the website to function and cannot be switched off in our systems. They are usually only set in response to actions made by you which amount to a request for services, such as setting your privacy preferences, logging in or filling in forms. You can set your browser to block or alert you about these cookies, but some parts of the site will not then work. These cookies do not store any personally identifiable information.

Performance Cookies

These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.