Why Do Flu Vaccines Contain Eggs? And What to Do if You Have an Egg Allergy?

young man giving a thumbs up sign while getting vaccinated

Reviewed by Dr Jackie Lam, M.B.B.S (Singapore)

Flu vaccines have long been a crucial tool in preventing the spread of influenza. However, one peculiar aspect of these vaccines often raises eyebrows: the inclusion of eggs in their production. In this article, we explore why flu vaccines contain eggs, the processes involved, and what individuals with egg allergies should consider.

The Role of Eggs in Flu Vaccine Production

Historical Connection

Since the 1940s, eggs have been an integral part of flu vaccine development. The influenza virus used in vaccines is often grown in fertilized chicken eggs. The process involves injecting the virus into the egg, allowing it to replicate, and then harvesting the virus for vaccine production.

Virus Adaptation

Influenza viruses have a natural affinity for avian hosts, making eggs a suitable medium for their growth. The virus adapts to the eggs’ environment during the cultivation process, ensuring it can effectively stimulate an immune response in humans when included in the vaccine.

The Dilemma for Individuals with Egg Allergies

Potential Allergic Reactions

While flu vaccines containing eggs are generally safe for most individuals, those with egg allergies face a potential risk. Allergic reactions can range from mild symptoms like hives to more severe reactions such as anaphylaxis. It’s crucial for individuals with egg allergies to take precautions when considering the flu vaccine.

Egg-Free Alternatives

Recognizing the concerns of individuals with egg allergies, researchers have developed egg-free alternatives for flu vaccines. These alternatives utilize different technologies, such as cell-based or recombinant methods, to grow the virus without the need for eggs. It’s advisable for those with egg allergies to opt for these alternatives when available.

Navigating Flu Vaccination with an Egg Allergy

Consultation with Healthcare Professionals

Individuals with egg allergies should consult their healthcare professionals before getting a flu vaccine. Allergy testing and discussions about the severity of the allergy can help determine the most appropriate course of action. In some cases, healthcare providers may recommend a graded approach, where the vaccine is administered in incremental doses under close observation.

Egg Tolerance Assessment

Healthcare providers may assess an individual’s tolerance to eggs before administering the flu vaccine. In most instances, individuals with egg allergies may still receive the traditional flu vaccine as severe reactions in people with egg allergies are rare. A recent CDC study found that only one in a million gets a life-threatening allergic reaction.

Your Health, Your Priority

The Importance of Preventive Care

Regardless of potential allergens, the importance of flu vaccination cannot be overstated. Influenza is a contagious respiratory illness that can lead to severe complications, especially in vulnerable populations. For optimal protection, it’s essential to prioritize preventive care, including timely flu vaccination.

Prioritize Your Health with Keystone Clinic & Surgery

Ensure your well-being by staying informed about flu vaccination and potential allergens. Keystone Clinic & Surgery offers comprehensive healthcare services. We do not carry egg-free alternatives, just like many clinics in Singapore. However, it is unlikely that you will suffer an allergic reaction. Nonetheless, do visit Keystone Clinic & Surgery for more information on flu vaccination and other preventive healthcare services.


Centers for Disease Control and Prevention. 2023. Flu Vaccine and People with Egg Allergies. https://www.cdc.gov/flu/prevent/egg-allergies.htm

Centers for Disease Control and Prevention. 2022. How Flu Vaccines Are Made. https://www.cdc.gov/flu/prevent/how-fluvaccine-made.htm

American Academy of Allergy, Asthma & Immunology. 2023. Egg Allergy and the Flu Vaccine. https://www.aaaai.org/tools-for-the-public/conditions-library/allergies/egg-allergy-and-the-flu-vaccine

WedMD. 2023. Influenza Vaccine (Flu Shot and Nasal Spray for Adults). https://www.webmd.com/vaccines/flu-shot-guidelines-for-adults

HealthHub. 2023. Flu Vaccinations. https://www.healthhub.sg/a-z/diseases-and-conditions/influenzafluvaccinationthebestwaytoavoidgettingtheflu#3 

Share this post