Vaccine Ingredient Safety

Vaccine ingredients are tested for safety before they are manufactured. Learn more about each ingredient:

Salts

  • Sodium & aluminum salts are used to normalize the salt balance in the human body
  • Some salts split the virus into smaller pieces to activate the immune system for adjuvanted vaccines

Sugars

  • Adding sugar stabilizes the vaccine ingredients so that they are less sensitive to heat/cold
  • The sugars used in vaccines are the same ones used to stabilize food products

Emulsifiers

  • Help mix ingredients that would normally not mix together (think oil + vinegar!)
  • The amounts used in vaccines are much smaller than what is used in other things you put into your body - like food and cosmetics

MF59 Adjustment

  • Only used in adjuvanted vaccines for people 65+ to create a stronger immune response
  • The main ingredient, squalene oil, occurs naturally in humans, animals, and plants

Thimerosal

  • Preservative used to prevent contamination in multi-dose vials
  • Most flu vaccines are single-vial and thus do not contain thimerosal
  • Thimerosal is metabolized by the body as ethylmercury, which is not the same as methylmercury, and does not cause poisoning

Formaldehyde

  • Formaldehyde is naturally occurring in apples, bananas, pears, and more
  • Used to kill the flu viruses so that the viruses in the vaccine teach your body to fight off and don't make you sick
  • The amount used in vaccines is much smaller than the amount that naturally occurs in the body

Antibiotics

  • Can be leftover from the manufacturing process to prevent contamination of bacteria into the vaccines
  • Most are removed during the purification process
  • The amount leftover is microscopic

Egg Protein

  • Only present in vaccines grown in eggs
  • Most is filtered out when the viruses are extracted from the eggs they were grown in