Do any vaccines contain pork-derived ingredients?

Vaccines and Pork-Derived Ingredients

No licensed vaccines contain pork as a primary ingredient, though some vaccines may contain porcine gelatin as a stabilizer. 1

Vaccine Components and Animal-Derived Ingredients

Vaccines may contain various components beyond the antigen itself, including:

• Stabilizers: Help maintain vaccine potency during manufacturing, storage, and transport
• Preservatives: Prevent contamination
• Adjuvants: Enhance immune response
• Residual components: From manufacturing process

Animal-Derived Components in Vaccines

1. Gelatin (including porcine gelatin)

   • Functions as a stabilizer in some vaccines
   • Present in MMR, MMRV, and some varicella and zoster vaccines 1
   • Hydrolyzed porcine gelatin is the most common form used 2
   • Some manufacturers have developed recombinant human gelatin alternatives 2

2. Egg protein

   • Found in influenza and yellow fever vaccines
   • Not derived from pork 1

Specific Vaccines Containing Porcine-Derived Ingredients

The only pork-derived ingredient commonly used in some vaccines is hydrolyzed porcine gelatin. This is primarily found in:

• MMR (measles, mumps, rubella) vaccine
• Varicella (chickenpox) vaccine
• Zoster (shingles) vaccine
• Some formulations of influenza vaccine

Allergic Reactions and Safety Considerations

Gelatin in vaccines can cause rare allergic reactions:

• Individuals with history of anaphylaxis to gelatin should exercise caution 1
• Skin testing for gelatin sensitivity may be considered before administering gelatin-containing vaccines to these individuals 1
• Recent research has identified potential concerns for patients with alpha-gal syndrome (red meat allergy) receiving gelatin-containing vaccines 3

Important Considerations for Patients

1. Religious or personal concerns: Patients with religious or personal objections to pork products should discuss with their healthcare provider which specific vaccines contain porcine-derived ingredients and potential alternatives.

2. Vaccine package inserts: The specific components of each vaccine are listed in the manufacturer's package insert and can be reviewed before vaccination.

3. Alternatives: For some vaccines, alternatives without porcine gelatin may be available. For example, research has shown that recombinant human gelatin can effectively replace porcine gelatin in certain vaccines 2.

Clinical Decision Making

When considering vaccination for patients concerned about pork-derived ingredients:

1. Identify if the specific vaccine formulation contains porcine gelatin
2. Discuss the purpose and importance of the vaccine
3. Consider available alternatives if appropriate
4. Weigh the health benefits against personal/religious concerns

The CDC maintains a comprehensive list of vaccine components that can be consulted to determine which specific vaccines contain gelatin or other animal-derived products 1.