Are there thimerosal-free flu shots?

Yes. Most single-dose, pre-filled syringes and nasal spray versions of the flu vaccine are thimerosal-free, according to the Centers for Disease Control and Prevention (CDC). Currently, only the multi-dose vials of flu vaccine contain thimerosal. All versions of the flu vaccine are considered safe by the CDC, though the shot method is currently understood to be more effective than the nasal spray version.  

Thimerosal has been used since the 1930s. Acting as a preservative, thimerosal prevents the growth of bacteria in multi-dose containers of vaccine. For the past few decades, thimerosal has been a source of concern among some researchers and parents because it contains mercury, which has been linked to an increased risk for developmental disorders including autism, in genetically susceptible individuals

Studies continue to refute any causal link between thimerosal and autism. But in an effort to ease public concern, the U.S. Public Health Service, the American Academy of Pediatrics (AAP), and vaccine manufacturers agreed in 1999 to reduce or eliminate thimerosal in vaccines “as a precautionary measure.” Since 2001, thimerosal has not been used in routinely recommended childhood vaccines—except for flu vaccines. 

Parents wanting more information on vaccine safety are urged to visit the following websites: Food and Drug Administration (FDA); Institute for Vaccine Safety; Centers for Disease Control and Prevention (CDC). 

Click here to learn more about the thimerosal-autism debate.

Last updated September 19, 2020

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