US Flu Vaccine Manufacturing: Domestic Production and Supply Chain

Influenza Vaccine Production in the United States

Yes, flu vaccines are manufactured in the US by multiple licensed facilities, ensuring domestic supply security.

Major US Manufacturers & Facilities

Company	Key US Facilities	Vaccine Types
Sanofi Pasteur	Swiftwater, PA	Fluzone (IIV4, high-dose, adjuvanted)
Seqirus (CSL)	Holly Springs, NC; Marburg, Germany (fill/finish)	Flucelvax (ccIIV4), Fluad (aIIV4), Afluria
GlaxoSmithKline (GSK)	Marietta, PA; Ste-Foy, QC (Canada)	Fluarix, FluLaval (IIV4)
MedImmune (AstraZeneca)	Liverpool, UK (primary); US fill/finish	FluMist (LAIV4)
Protein Sciences (Sanofi)	Meriden, CT	Flublok (RIV4, recombinant)

Production Timeline

1. WHO strain selection (Feb for NH).
2. Candidate vaccine viruses (CVVs) developed.
3. Egg-based: CVVs inoculated into embryonated eggs (6-8 months).
4. Cell-based (Flucelvax): Mammalian cells – faster, no egg adaptation.
5. Recombinant (Flublok): Baculovirus/insect cells – fastest, no egg/cell culture.
6. Fill/finish, lot release, FDA approval, distribution.

Supply Resilience

• Multiple platforms (egg, cell, recombinant) mitigate single-point failures.
• US government contracts (BARDA) support capacity expansion and pandemic preparedness.
• Annual US supply: ~170-200 million doses.

All US-licensed flu vaccines meet FDA standards regardless of manufacturing origin.