vaccines mercuryVaccines (link to our vaccines community pages) are antigenic substances, produced from the agent of a disease, used to provide immunity against one or several diseases. the process of culturing vaccines has yielded effective treatment against disease.


Vaccines Save Lives, Billions of Lives

As a child of the 1970s growing up in the UK, I’ve never witnessed polio but I know of relatives lost to the disease in the 50s. However, widespread vaccination programs in the late 50s and 60s meant that domestically acquired cases of the disease were practically zero by the time I reached school. Not just polio, vaccinations have meant that I’ve never needed to have concern for smallpox, diphtheria, tuberculosis and numerous other diseases.

And, those in my country who were unable to receive vaccinations because of allergies or severe illness such as cancer, are also thankfully protected due to herd immunity (EU vaccines page). Herd immunity occurs when the near complete vaccination of a population provides a measure of protection for individuals who have not developed immunity. However, when the immunized population falls, herd immunity can break down, resulting in an increased prevalence of disease. This is seen more and more frequently in the developed world when parents refuse immunization for their children. This choice causes outbreaks to develop; such as a measles outbreak in Swansea in 2013 (link to new story)that resulted in tragic loss of life.


So What Makes People Mad About Vaccines?

Mercury makes people mad (literally): For centuries, mercury compounds were used to soften hat making felts. Elemental mercury vapors were released from the treated felts and furs; consequently, hatters were exposed to high levels of mercury through inhalation. A powerful neuro-toxicant, mercury causes dementia and behavioral disorders. Hence the expression “mad as a hatter” was coined from occupationally related mercury poisoning.

Organomercury (link to Wikipedia page) compounds have a variety of positive uses as antibacterial, antiseptic and antifungal agents. One compound, Thiomersal (link to WHO site) contains small amounts of mercury and is a very effective preservative used as an ingredient in vaccine preparations to ensure the product remains sterile during storage by preventing the growth of bacteria or fungi.


“no evidence of mercury toxicity in infants, children, or adults exposed to thiomersal in vaccines.” WHO


Thiomersal makes people mad (figuratively): There have been many high-profile concerns recently that thiomersal-containing vaccines can cause autism. Vocal campaigners, such as Robert F. Kennedy Jr., (link to news story) have lobbied regulatory agencies and governments for its removal from all vaccines. The World Health Organization (WHO) has stated that there is there is no evidence of mercury toxicity in infants, children, or adults exposed to thiomersal in vaccines.


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Analyzing Mercury in Vaccine

Despite no solid evidence for the toxicity of thiomersal; its use in vaccines has become less popular due to tabloid hype around the additive. Yet, there are few substitute ingredients that are as well established or effective; consequently its use will continue. Thiomersal metabolizes to ethyl-mercury which does not readily bio-accumulate and is rapidly removed from the body, so it presents a low toxicological risk.

Regulatory agencies and clinical researchers have looked to analytical methods to analyze the various species of mercury pharmaceutical preparations, and clinical samples, together with other heavy metals that may also present a toxicological risk.


  • APPLICATION NOTE: Thiomersal mercury species can be easily analyzed through combination of ion chromatography (IC) and inductively coupled plasma mass spectrometry (ICP-MS), as shown in this IC-ICP-MS application (downloadable PDF).



Thankfully, in my job I get insight into the advanced analytical science that pharmaceutical regulatory agencies use to analyze contaminants at levels orders of magnitude lower than their toxicological significance. This data leads organizations such as U.S. Food and Drug Administration, European Medicines Agency and World Health Organization to give advice based on sound scientific evidence. Consequently, I had no hesitation to vaccinate my child last year, as much for her safety as for the rest of our herd.


Additional Resources

To find out more about how mercury and other toxic metals can be analyzed in pharmaceutical preparations visit our dedicated trace metal analysis website that details methods to meet the latest ICH Q3D guidelines and methods from USP <232>, <233> and <2232>.

Also, do check out our Pharma & Biopharma Community which is a wonderful resource, totally dedicated to the development and production of tomorrow’s medicines. It features the latest on-demand webinars, videos, application notes, and more.


Are you concerned about the presence of mercury in vaccine? Would like to hear your opinion on this very controversial subject.