Yeast in vaccines?

Yes, a few vaccines may contain trace amounts of yeast proteins.

Why?

Those vaccines are actually made in baker’s yeast (the growth medium), kind of like other vaccines are grown in cell cultures, etc. And although most of the yeast proteins are removed as the vaccine antigens are removed and purified, some residual yeast proteins remain in the vaccine.

For more information:

• Ingredients in Vaccines
• Can people with yeast allergies get vaccines?

• Vaccine Ingredients