Skip to content

Are vaccine ingredients safe?

The Claim:

A viral tweet repeats an old trope about the dangers of vaccine ingredients, including aluminum, thimerosal, and formaldehyde.

The Facts:

Babies are subjected to more challenges to their immune system at birth than they will be in the entire immunization schedule. Keep in mind that the amount of any ingredient in vaccines is very small–smaller than what a child will encounter naturally through living and breathing and eating

Aluminum is the third most abundant element on earth and is present in many of the foods we eat, in much higher quantities than found in vaccines. Any aluminum injected from vaccines is metabolized in the body, and the vast majority of it is excreted within weeks

Because the blood-brain barrier is actually quite good at keeping out those things it doesn’t need, such as proteins and viruses, we can be assured that aluminum adjuvants do not cross this barrier. This excellent video by Dr. Paul Offit explains the details about how the BBB works to protect us and our brains.

We know a lot now about thimerosal. Thimerosal, a mercury compound used today in some flu vaccines, has caused concern due to its name being confused with a harmful type of mercury. Thimerosal contains ethylmercury, which is safe and quickly leaves the body. It’s different from harmful methylmercury found in some fish. Thimerosal has been used safely in vaccines, drugs, and contact solutions since the 1930s. Nowadays, most vaccines use single-use vials, and thimerosal-free vaccines are available for those still concerned.

Formaldehyde has been used in some vaccines for many years to inactivate viruses or detoxify bacteria so the vaccines don’t cause sickness. If you’re not an organic chemistry expert that can sound scary but here are the facts:

Formaldehyde is actually naturally in our bodies; it’s vital for our metabolic process. Like everything, the amount of formaldehyde in your body determines whether it is dangerous. Vaccines have an extremely small amount of formaldehyde. The highest amount found in a dose of vaccine is 0.02 mg, but a newborn will have about 50 times that naturally in their body

Disclaimer: Science is always evolving and our understanding of these topics may have evolved too since this was originally posted. Be sure to check out our most recent posts and browse the latest Just the Facts Topics for the latest.

Just the Facts Newsletter:

Correcting this week's disinformation

Sign up to get a weekly look at the latest vaccination facts as we debunk the latest false vaccination claims making the rounds on the internet.


Back To Top