The Truth About Vaccines and Food Allergies

Vaccines don't cause food allergies, but people with existing egg allergies do need to be cautious when receiving certain vaccines. Here's what parents need to know about vaccines and food allergies.

Vaccines don't cause food allergies, but some people with existing food allergies may need to be cautious about certain vaccines, as they contain ingredients that could cause them to develop an allergic reaction. Here's what parents need to know about vaccines and food allergies.

Vaccines, Food Allergies, and the Hygiene Hypothesis

Why are some people misled into thinking that vaccines cause food allergies? Vaccine expert Dr. Paul A. Offitt, the director of the Vaccine Education Center at the Children's Hospital of Philadelphia, believes this is because of the "hygiene hypothesis."

According to the hygiene hypothesis, the less exposure a child has to common infections, and the more hygienic their family's home habits are overall, the more likely they are to develop a food allergy. Several studies support the hygiene hypothesis.

But at the same time, vaccines don't affect the hygiene hypothesis or increase someone's food allergy risk. This is because most of the infections tied to the hygiene hypothesis, and most of the illnesses usually caught in childhood, can't be prevented through a vaccine. Common childhood infections of the respiratory tract (like the common cold) do play into the hygiene hypothesis, and supposedly lessen a child's food allergy risk. Meanwhile, diseases that a vaccine can prevent spread easily regardless of a family's home hygiene, and don't affect the hygiene hypothesis.

Studies Show: Vaccines Don't Cause Food Allergies

The fact that vaccines don't cause food allergies has been proven by several well-controlled studies.

One Swedish study evaluated 669 children who either received a diptheria-tetanus-pertussis (DTaP) vaccine or a placebo, to see if the vaccine increased the risk of certain allergic conditions (food allergies, asthma, skin reactions, hives and hay fever). Infants received the shot (vaccine or placebo) beginning at 2 months of age, and were followed for two and a half years.

The study found that the DTaP vaccine group wasn't more likely to develop an allergic condition than the placebo group. So, it showed that the vaccine didn't cause food allergies, or increase the risk of other related allergic conditions.

Another study, an Australian cohort study, followed 5500 individuals from age 7 to age 44. This study examined the vaccines the individuals received in childhood and any allergic conditions they developed (food allergies, eczema, asthma or hay fever) to see if there were any associations. The study found that none of the vaccines the individuals received (diphtheria, tetanus, pertussis, polio, and smallpox) made them more likely to have an allergic condition. Again, this showed that vaccines don't cause food allergies.

Because of this, you shouldn't delay or avoid vaccines out of fear or food allergies.

You shouldn't delay or avoid vaccines out of fear or food allergies.

Vaccines don't increase someone's food allergy risk. But, as studies have also shown, delaying or refusing a vaccine for your child puts them at risk for fully preventable infectious diseases.

"Anecdotal reports and uncontrolled studies have proposed that vaccines may cause particular allergic or autoimmune diseases. Such reports have led some parents to delay or withhold vaccinations for their children. This is very unfortunate, because the best available scientific evidence does not support the idea that vaccines cause chronic diseases." ---Dr. Paul A. Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia

“The best available scientific evidence does not support the idea that vaccines cause chronic diseases." - Dr. Paul A. Offit

The Real Risk Factors For Food Allergy

What factors do increase a child's food allergy risk? Hygiene is one of them, but it's not a main risk factor. The main risk factors for food allergies are eczema, a family history of food allergy. (Learn more about food allergy risk factors here.)

While the first two main risk factors are out of parents' control, you can take action to maintain early exposure. As landmark studies show, the best thing a parent can do is to feed their baby common allergy-causing foods (peanut, egg, and milk) early and often, starting as early as 4 months of age.

Ready. Set. Food! Is Safe, Even Right After A Vaccination Appointment

Ready. Set. Food! makes it easy to introduce peanut, egg, and milk to your baby early and often.

Many parents wonder, though, if Ready. Set. Food! is safe to feed babies right after a vaccination appointment.

Yes, Ready. Set. Food! is safe to feed to your baby after a vaccination appointment. So, you shouldn't skip a daily dose of Ready. Set. Food! just because your baby is receiving a routine vaccination. Early and consistent exposure is key, and vaccines won't make your baby more likely to develop a food allergy. Feel free to consult with your pediatrician, though, if you have additional concerns about using Ready. Set. Food! after a vaccination appointment.

Vaccines and Safety: When Your Child Already Has A Food Allergy

Even though vaccines don't cause food allergies, some people with existing food allergies still need to be cautious about certain vaccines. If a vaccine contains a food that they are already allergic to, it may cause them to develop an allergic reaction. They might even develop anaphylaxis, a severe allergic reaction that requires immediate emergency attention.

Egg Allergies and the Flu Vaccine

The main concern is the influenza vaccine (flu vaccine) for people with egg allergies, because most forms of the flu vaccine contain a small amount of egg protein. The egg in the flu shot has the potential to cause an allergic reaction.

The likelihood that the vaccine will cause a severe allergic reaction, though, is small, because the amount of egg protein in the vaccine is so low. Plus, the vaccine is vital for preventing the flu, so the benefits outweigh that small risk of a severe allergic reaction. Given this, the CDC still recommends that people with egg allergies receive the standard flu vaccine for their age. People with egg allergies also don't need to be observed for half-hour periods after receiving the vaccines.

In this video, Dr. Paul Offit talks about vaccines and existing food allergies:

However, people who have had a moderate or severe reaction to egg, including any symptoms other than hives, still need to be cautious when receiving the flu vaccine. They should only receive the flu vaccine in an inpatient or outpatient setting, such as a hospital or physician's office. The vaccination should also be supervised by a health care provider who knows how to identify and manage a severe allergic reaction. The health care provider must be aware that the person receiving the vaccine is allergic to egg, for maximum safety.

People over 4 years of age who have experienced an allergic reaction to egg can also receive a flu vaccine that doesn't contain any egg. This vaccine is called Flucelvax Quadrivalent. Another eggless flu vaccine is also available, but it's only approved for adults.

The only reason why a person with egg allergy shouldn't receive a flu vaccine is if they have had a previous severe reaction to the vaccine itself. So, if your child had a previous severe allergic reaction to egg, but not to the vaccine, they should still get vaccinated against the flu.

Egg Allergy and Other Vaccines

Other vaccines that parents with egg-allergic children may be concerned about are the measles-mumps-rubella (MMR) vaccine and the yellow fever vaccine.

The MMR vaccine, a routine vaccine for children, is usually produced with the cell cultures of chicken embryos. Even with the connection to chicken and eggs, though, it contains few to no proteins that could cause an egg allergy reaction. So, according to the American Academy of Pediatrics (AAP), children with egg allergies should still receive the MMR vaccine. No special precautions need to be taken, but your doctor may want to monitor your egg-allergic child for a short period after they receive the vaccine. Most egg-allergic children won't have a significant allergic reaction to the MMR vaccine.

The yellow fever vaccine, on the other hand, is dangerous for people with egg allergy. It contains very high amounts of egg protein---the highest amounts of any vaccine that contains egg. So, people with any egg allergy should not receive the yellow fever vaccine. (The yellow fever vaccine is not a routine vaccine, though; it's usually only given to people who travel to certain regions of South America and Africa.)

Introduce Allergens Safely and Easily with Ready. Set. Food!

All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.

These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure or prevent any disease.  If your infant has severe eczema, check with your infant’s healthcare provider before feeding foods containing ground peanuts.