The Truth About Vaccines and Food Allergies

Vaccines don't cause food allergies. 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."

The Hygiene Hypothesis posits that early exposure to many microbes acts as training for the immune system. When babies have less exposure to microbes, their immune system may be less functional and that could result in allergies. In the last 50 years, according to the Hygiene Hypothesis, the overuse of antibacterial soaps, unnecessary use of antibiotics (like when they’re prescribed for a viral infection they can’t treat), and less exposure to the outdoors and animals have triggered the allergy epidemic. Many people think that the Hygiene Hypothesis is about getting sick, which is why some people incorrectly believe that vaccines, which prevent illness, might be preventing immune system development, contributing to allergies. 

However, the Hygiene Hypothesis is not about actual illnesses, it is about exposure to many different things. Vaccines do not prevent your baby from being exposed to many microbes and therefore aren’t a factor in 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, and delayed introduction of common allergens. (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 allergen 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

If your child has an egg allergy, they should still get the flu vaccine. Previously, egg allergic individuals were cautioned about the flu vaccine, but research has now proven it is safe. And the flu vaccine is particularly important for young children, including those with egg allergies. 

As the American Academy of Allergy, Asthma, and Immunology (AAAAI) affirms, "There are hundreds of thousands of hospitalizations, and tens of thousands of deaths in the United States every year because of the flu, most of which could be prevented with a flu shot. Egg allergy primarily affects young children, who are also particularly vulnerable to the flu... Everyone, including children with egg allergy, is encouraged to get a flu shot."

People with egg allergies don't need to take extra precautions when receiving the flu vaccine (beyond the normal safety precautions needed when someone receives any type of vaccine). This is because the flu vaccine doesn't have enough egg protein inside to trigger an allergic reaction, even for people with a history of severe egg allergy reactions. 

This means that people with egg allergies:

  • Can get a flu vaccine from any medical professional – they don't need to go to an allergist
  • Don't have to wait for any extra amount of time after getting the vaccine
  • Can receive any type of flu vaccine that's appropriate for their age group, whether it contains egg or not
  • Don't have to alert the medical professional about their egg allergy (or have parents or caregivers notify the medical professional) before they receive the vaccine

Thousands of people with egg allergies, in dozens of studies, haven't had an allergic reaction after getting the flu vaccine. As the Centers for Disease Control and Prevention (CDC) reports, "Studies that have examined the use of both the nasal spray vaccine and flu shots in egg-allergic and non-egg-allergic patients indicate that severe allergic reactions in people with egg allergies are unlikely." 

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

If your child has an egg allergy, there's no need to be concerned about the measles-mumps-rubella (MMR) vaccine. Even though the MMR vaccine is usually produced with the cell cultures of chicken embryos, and is connected to chicken and eggs, 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 routine MMR vaccine. No special precautions need to be taken. Still, 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.