In 1991, Dr. John Kelso saw a 17-year-old girl who developed a severe allergic reaction (hives, low blood pressure, runny nose and lightheadedness) within five minutes of receiving an MMR (measles, mumps and rubella) vaccine. Her symptoms resolved after treatment with epinephrine. When she described the event to him, she said that it was “kind of like what happens when I eat Jell-O.” The girl underwent allergy testing, which identified only one component of the MMR vaccine to which she was allergic: gelatin.

About gelatin

Gelatin is made from collagen, a protein common in skin. To make gelatin from collagen, skin, hooves and connective tissues from cows or pigs are boiled or treated chemically. 

Gelatin is used in a variety of products:

• Foods, like Jello, pudding, marshmallows, ice cream, cheeses and some other dairy products and desserts
• Inks and photographic films and papers
• Plastics
• Matches
• Cosmetics 
• Ointments
• Blood substitutes and extenders
• Pharmaceutical capsules
• Vaccines

Foods are the most common source of exposure to gelatin. 

Gelatin in vaccines

Gelatin is a stabilizer used in some vaccines. This means it protects the vaccine during transport and delivery so that the vaccine works as it is expected to when administered. 

The gelatin contained in most vaccines is from pigs. One exception is the rabies vaccines, called Rabavert, which uses gelatin from cows.

Jews, Muslims and Seventh Day Adventists prohibit consumption of pig products. Because of the use of gelatin derived from pigs in some vaccines, questions sometimes arise about whether members of these groups can use vaccines that contain gelatin. The short answer is yes. The policymaking authorities of these groups have approved the use of vaccines containing gelatin for several reasons:

• Most vaccines are not given by mouth. The one routinely recommended U.S. vaccine that is given by mouth is the rotavirus vaccine, which does not contain gelatin. The capsule of the oral typhoid vaccine is also composed of gelatin, but that vaccine is only recommended for certain groups of travelers.
• The gelatin contained in vaccines is highly purified and different from the starting ingredient of collagen found in nature.
• The benefits of receiving vaccines outweigh the considerations related to following the religion’s dietary rules.

The table below shows quantities of gelatin in different vaccines approved for use in the U.S. as of June 2026.

* Note: The gelatin product used in this vaccine is of bovine origin.

Health effects of gelatin

As described in the example above, some people are allergic to gelatin when eaten or injected. These individuals can have a severe allergic reaction that causes hives; itching; swelling of the lips, tongue or throat; difficulty breathing; dizziness or fainting, among other symptoms. These reactions occur shortly after exposure to gelatin and can be a medical emergency.  

Gelatin in vaccines and health

Studies in Japan confirmed that severe allergic reactions to MMR vaccine were associated with the presence of antibodies in the blood directed against gelatin. Although the incidence of anaphylaxis to gelatin is extremely low (about 1 case per 2 million doses), gelatin is the most common identifiable cause of severe allergic reactions to vaccines.

People with severe allergies to gelatin should avoid gelatin-containing vaccines.

Severe allergic reactions occur very soon after exposure to the allergen, so as with other vaccines, it is recommended to stay at the place where the vaccine was given for 15-30 minutes after vaccination. Healthcare personnel are trained to respond in the event of a reaction.

Summary

Gelatin is used in many foods and other products, including some medical products. It is used in some live, weakened vaccines as a stabilizer to ensure that the vaccines work as they should when administered. A small number of people are allergic to gelatin. Severe allergic reactions can be frightening and life-threatening. For this reason, people who are allergic to gelatin should not receive vaccines that contain this ingredient.

References

Kelso JM. The gelatin story. J Allergy Clin Immunol. 1999;103(2):200-202.

Nakayama T, Aizawa C. Change in gelatin content of vaccines associated with reduction in reports of allergic reactions. J Allergy Clin Immunol. 2000;106:591-592.

Sakaguchi M, Nakayama T, Fujita H, et al. Minimum estimated incidence in Japan of anaphylaxis to live virus vaccines including gelatin. Vaccine. 2001;19:431-436.

Sakaguchi M, Nakayama T, Inouye S. Food allergy to gelatin in children with systemic immediate-type reactions, including anaphylaxis, to vaccines. J Allergy Clin Immunol. 1996;98:1058-1061.

Sakaguchi M, Yamanaka T, Ikeda K, et al. IgE-mediated systemic reactions to gelatin included in the varicella vaccine. J Allergy Clin Immunol. 1997;99:263-264.

Sakaguchi M, Hori H, Ebihara T, et al. Reactivity of the immunoglobulin E in bovine gelatin-sensitive children to gelatins from other animals. Immunology. 1999;96:286-290.

Sakai Y, Yamoto R, Onuma M, et al. Non-antigenic and low allergic gelatin produced by specific digestion with enzyme-coupled matrix. Biol Pharm Bull. 1998;21:330-334.