Fluad is not egg-free. The vaccine is manufactured using chicken eggs, and each dose may contain up to 1.0 microgram of residual egg protein (ovalbumin). If you’re looking for a completely egg-free flu vaccine, other options exist, but Fluad isn’t one of them.
Why Fluad Contains Egg Protein
Like most flu vaccines, Fluad is made by growing influenza viruses inside fertilized chicken eggs. The viruses are then harvested, purified, and inactivated. Despite thorough purification, tiny amounts of egg protein carry over into the final product. The FDA-approved package insert lists residual ovalbumin at no more than 1.0 microgram per dose, which is an extremely small quantity but not zero.
Fluad also contains an adjuvant called MF59, which is the feature that distinguishes it from standard flu shots. MF59 is made of squalene (a naturally occurring oil), polysorbate 80, sorbitan trioleate, sodium citrate, and citric acid. None of these adjuvant ingredients come from eggs, but the underlying vaccine itself still does.
Who Fluad Is Designed For
Fluad Quadrivalent is specifically approved for adults 65 and older. The MF59 adjuvant helps stimulate a stronger immune response, which matters in older adults whose immune systems typically respond less robustly to standard flu shots. It is not approved for younger adults or children.
Egg Allergies and Flu Vaccines
Even though Fluad contains trace egg protein, the CDC states that people with egg allergies can receive any flu vaccine, including egg-based ones like Fluad, that is appropriate for their age and health status. This guidance applies regardless of how severe the egg allergy is. Beginning with the 2023-2024 season, the CDC dropped its previous recommendation for extra safety precautions (like extended observation periods) when vaccinating egg-allergic individuals. Studies examining flu shots in egg-allergic patients found that severe allergic reactions are unlikely.
That said, if avoiding egg protein entirely is important to you, egg-free alternatives do exist.
Egg-Free Flu Vaccine Options
Two types of flu vaccines licensed in the United States are completely egg-free:
- Recombinant flu vaccine (Flublok Quadrivalent): Made using recombinant technology, which never involves chicken eggs or egg-grown viruses at any stage of production. It is approved for adults 18 and older.
- Cell culture-based flu vaccine (Flucelvax Quadrivalent): Grown in animal cell cultures rather than eggs. It is approved for people 6 months and older.
Neither of these is specifically designed for older adults the way Fluad is, so they don’t include an adjuvant to boost immune response. If you’re 65 or older and want both an egg-free vaccine and an enhanced immune response, that’s a tradeoff worth discussing with your pharmacist or doctor, since no egg-free adjuvanted flu vaccine is currently available.
The Bottom Line on Fluad and Eggs
Fluad contains trace egg protein from its manufacturing process. The amount is tiny, at 1 microgram or less per dose, and current CDC guidance says egg-allergic individuals can safely receive it. But if you need or prefer a vaccine with zero egg involvement, Flublok and Flucelvax are the two egg-free options on the market.