Animal Products in Vaccines

Are there animal products in vaccines?

This question is common, particularly related to concerns of gelatin and eggs. Like other common questions related to COVID-19 or other vaccines and aborted fetal cells, it has been my experience that the vast majority of those asking such questions are simply trying to align their vaccine decision with their personal values and beliefs, of which vary from person to person. 

Thus, the goal here is to provide a basic overview, a starting point, of information and resources to help you make informed decisions for yourself and your family.^a 

Animal Cells

Most vaccines are grown with non-human cells, such as animals, insects, chicken eggs, or yeast. Unfortunately, to my knowledge, the only way to find such information is to look at the specific vaccine manufacturing process, talk to your primary care and/or vaccine provider, or contact your local health department.

For example, the Flucelvax® Quadrivalent is one of the most widely released influenza (flu) vaccines for the 2021-2022 flu season by the FDA.1 According to its package insert, Flucelvax used cell lines from Madin Darby Canine [dog] Kidney (MDCK) cells, thus they state that each dose, “may contain residual amounts of MDCK cell protein,” and “MDCK cell DNA,” among other ingredients.²

Egg

Avian (bird) cells are one of the most common types of cells used for growing vaccines—especially within fertilized chicken eggs, perhaps due to their low cost, high volume, and tradition of use. As a result, however, egg proteins (primarily ovalbumin found in egg whites) can be present in vaccines.³ 

Egg allergy is one of the more common food allergies in children, and can be life-threatening. The Vaccine Education Center of Children’s Hospital of Philadelphia provides a regularly updated article on egg allergies and vaccines [LINK HERE]—particularly:

1. Influenza (flu) vaccines
   1. For 2021-2022 flu season, two vaccines licensed for use in the US were manufactured without eggs, thus considered ‘egg-free’:⁴
      1. Flublock® Quadrivalent (for adults 18 years and older)
      2. Flucelvax® Quadrivalent (for people 6 months and older)
2. Yellow fever vaccines 

According to the FDA, the COVID-19 vaccines approved for use in the US do not contain eggs.⁵

NOTE: If there is concern of being allergic to eggs, please make an appointment with your primary care provider and an allergist before getting these vaccines. General information on the flu vaccine and people with egg allergies can be found HERE.⁴

Gelatin

Gelatin is defined by the FDA as, “a product that has been obtained by the partial hydrolysis of collagen derived from hides, connective tissue, and/or bones of cattle and swine.”⁶ Simply put, gelatin is a protein byproduct that comes from boiling animal bones, tendons, ligaments, and other tissues in water. 

Gelatin is widely used in the food, cosmetic, and pharmaceutical industries. It can be found in hard and soft gelatin (‘gel’) capsules, tablets, suppositories, and syrup-based medications. Check the ingredient lists next time you pick up any of these items.

For vaccines, gelatin is often used as a ‘stabilizer,’ to help protect the vaccine from adverse conditions (e.g., freeze-drying, heat exposure), and to keep the vaccine effective after manufacturing. The Vaccine Education Center of Children’s Hospital of Philadelphia provides a regularly updated, quick list of common vaccines licensed for use in the United States that contain gelatin [LINK HERE]—particularly for:⁷

1. Influenza (flu)
2. Measles, Mumps, Rubella (MMR)
3. Rabies
4. Typhoid
5. Varicella
6. Yellow Fever

According to the FDA, the COVID-19 vaccines approved for use in the US do not contain gelatin.⁵

Fetal Calf/Bovine Serum

When vaccines are grown in cells, the “cells need a source of nutrition, which in some instances may be provided by fetal bovine serum.”⁸ Fetal bovine serum (FBS) is blood serum obtained from a living unborn calf removed from a slaughtered cow, mostly through a heart puncture.^9,10 FBS is one of, if not the most common medium for growing vaccine cell cultures, but is not a part of the vaccine itself.  

Licensed Vaccine List 

For all vaccines licensed for use in the United States, please click the link below.

https://www.fda.gov/vaccines-blood-biologics/vaccines/vaccines-licensed-use-united-states

References 

1. https://www.fda.gov/vaccines-blood-biologics/lot-release/influenza-vaccine-2021-2022-season
2. https://www.fda.gov/media/115862/download
3. https://www.chop.edu/centers-programs/vaccine-education-center/vaccine-ingredients/egg-products
4. https://www.cdc.gov/flu/prevent/egg-allergies.htm
5. https://www.fda.gov/news-events/rumor-control
6. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=189.5
7. https://www.chop.edu/centers-programs/vaccine-education-center/vaccine-ingredients/gelatin
8. https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/common-ingredients-us-licensed-vaccines
9. van der Valk, J., & Gstraunthaler, G. (2017). Fetal bovine serum (FBS)—a pain in the dish? Alternatives to Laboratory Animals, 45(6), 329-332.
10. Van der Valk, J., Mellor, D., Brands, R., Fischer, R., Gruber, F., Gstraunthaler, G., ... & Baumans, V. (2004). The humane collection of fetal bovine serum and possibilities for serum-free cell and tissue culture. Toxicology in vitro, 18(1), 1-12.

^aDisclaimer: These links and resources are provided for informational purposes only. They do not constitute an endorsement or an approval by the Well Church Initiative and Texas A&M AgriLife Extension of any of the products, services or opinions of the corporation or organization or individual. Please consult an appropriate healthcare provider for specific advice on vaccines tailored to your situation.