“My daughter has a corn allergy; do I need to worry about her getting vaccines?”

“I heard the rise in peanut allergies is because peanut oils are used in vaccines. Is this true?”

Both questions are related to the notion that oils in vaccines can cause allergic reactions in those who have food sensitivities. Indeed, if someone has a sensitivity to a vaccine component, they may be advised not to get it; however, vaccines do not contain either corn or peanut oils. Typically, oils would be introduced in vaccines as adjuvants. One example is squalene, which is made from shark liver oil. It is included in the adjuvant called MF59.

About corn and peanut oils

As their names indicate, these oils come from specific foods. 

Corn does not have large amounts of oil, so the process of making corn oil involves several steps. Corn oil is commonly used for cooking. It is also found in many other products, including industrial cleaners, engine lubricants, cosmetics, soaps and shampoos. 

Peanut oil is another type of oil commonly used in cooking. It is also used in some medications and creams.

About squalene, an oil used as an adjuvant in vaccines

Squalene is taken from fish oil, specifically shark liver oil. Squalene is also made in our livers and is found in our bloodstreams as part of cholesterol synthesis.

Squalene can be found in some medications, cosmetics, fragrances and hair products. It is also approved for use as an adjuvant in vaccines. Adjuvants improve the immune response to vaccines. 

When squalene is used as an adjuvant, it is mixed with water. Compounds made of mixtures of water and oil are called emulsions. The only U.S. vaccine that currently contains squalene is an influenza vaccine for adults 65 and older, called Fluad.

Health effects of corn and peanut oils

Studies of the health effects of corn oil are mixed, and corn oil is a highly processed substance. As such, it is generally recommended to use other types of oils for cooking when possible.

People who have peanut allergies may have reactions to products that contain peanut oils, but the risk depends on a variety of factors, including the severity of the allergy and the quantity and form of the peanut oil in the product.

No vaccines currently used in the U.S. contain either corn or peanut oils.

Health effects of squalene

Everyone has squalene in their bodies. It is created when the body makes cholesterol. When people eat squalene in food, about 60% is absorbed into the bloodstream before being deposited in different tissues. The most common place it is deposited is in the skin, where it becomes part of lipids found at the surface of the skin.

Squalene in the diet may help control cholesterol levels, but more evidence is needed. Likewise, some data suggest that it can help increase the effectiveness of certain cancer therapies, but clinical trials are needed to understand whether this is the case.

Summary

While corn and peanut oils may cause allergic reactions in some people, vaccines do not contain these oils. Squalene, a shark liver oil, is contained in the vaccine adjuvant called MF59. Everyone has squalene in their bodies because it is made during cholesterol production. As such, people are not known to have allergic reactions to this chemical.