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Vaccine Thimerosal Flu
About Vaccine Thimerosal Flu
After thimerosal was removed from childhood vaccines by 2001, it remained in multi dose vials of influenza vaccine. The CDC recommended flu vaccination for all children 6 to 23 months in 2004 and expanded to all children 6 months to 5 years in 2006. Thimerosal free flu vaccines were available but limited in supply. Some parents refused flu vaccines containing thimerosal, leading to lower coverage. Thimerosal free flu vaccines became widely available in single dose vials and prefilled syringes, and in 2025 US health officials adopted a policy of using only thimerosal free flu vaccines. The AAP and CDC state that thimerosal free formulations are available for parents who prefer them while emphasizing that thimerosal containing vaccines are safe. The continued presence of thimerosal in some flu vaccines reflects manufacturing and cost considerations. The WHO supports the use of thimerosal in vaccines globally as safe and essential for multi dose vial packaging.
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