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H1N1 Flu Vaccine – Why the Delay?

[Announcer] This podcast is presented by the Centers for Disease Control and Prevention. CDC – safer, healthier people.

[Dr. Thomas Frieden] Clearly, the vaccine production technologies need to continue to improve. We're still using eggs. We're still using technologies that have been around for a long time. We did not cut any corners in terms of vaccine safety. All of the safeguards are being used. We're using the same production methods, the same factories, the same companies, the same safeguards to make a vaccine that's been used for hundreds of millions of doses with an excellent safety record.

[Narrator] Influenza vaccine production begins as early as 9 months before vaccine becomes available. Each production cycle begins by selecting the strains that are the best match to the flu strains anticipated to be circulating during the upcoming flu season. Mass production of each of the virus strains occurs from January to July. Each of the vaccine strains is produced separately by injecting live virus into millions of fertilized hens' eggs. The manufacturers then begin putting doses into vials, syringes, or nasal sprayers while waiting for FDA approval to release lots. However, each lot must be approved separately for release by the FDA prior to shipment.

Manufacturers and the FDA test vaccine at multiple stages of production to ensure it is safe and ready for shipping.

[Dr. Thomas Frieden] It's challenging with a limited amount of vaccine for a lot of people who want to get vaccinated. This means that asking your provider, checking with your health department, checking on flu.gov may be necessary, whereas we wish that it would be easier for people to find out where they could easily get vaccinated.

[Announcer] For the most accurate health information, visit www.cdc.gov or call 1-800-CDC-INFO, 24/7.