The first seasonal influenza vaccine licensed in the United States produced using cultured animal cells instead of fertilized chicken eggs has been approved by the US Food and Drug Administration (FDA).
Flucelvax (Novartis Vaccines and Diagnostics GmbH) is an inactivated vaccine indicated for active immunization for the prevention of influenza disease caused by influenza virus subtypes A and type B in people aged 18 years and older. Although other vaccines have been produced using cell culture, this approval represents the first time an influenza vaccine using this technique has been approved.
According to an FDA news release, cell culture technology represents an alternative to conventional egg-based influenza vaccine production. Although the production processes are similar, a difference is that the virus strains included in the vaccine are grown in animal cells of mammalian origin instead of in eggs.
"Advantages of cell culture technology include the ability to maintain an adequate supply of readily available, previously tested and characterized cells for use in vaccine production and the potential for a faster start-up of the vaccine manufacturing process in the event of a pandemic," the FDA states in a news release.
The approval was based on data from a randomized trial including about 7700 adults younger than 50 years in the United States and Europe. Compared with placebo, the vaccine demonstrated 83.8% efficacy in preventing influenza.
Adverse events associated with the vaccine were evaluated in about 6700 individuals and were comparable to those observed with other influenza vaccines, including injection site reactions, headache, and fatigue.
Centers for Disease Control and Prevention guidelines state that everyone who is at least 6 months of age should get an influenza vaccine this season. Currently, 3 types of trivalent inactivated vaccine are available in the United States:
a regular trivalent inactivated vaccine given intramuscularly is approved for people 6 months of age and older, including healthy people, those with chronic medical conditions, and pregnant women;
a "high-dose" trivalent inactivated vaccine also given intramuscularly containing 4 times the amount of antigen as the regular trivalent inactivated vaccine that is approved for use in people aged 65 years and older; and
an intradermal trivalent inactivated vaccine that is injected into the dermal layer of the skin via a single-dose, prefilled microinjection syringe and that contains less antigen than the intramuscular trivalent inactivated vaccine formulations was approved for use in people aged 18 through 64 years in 2011.
In addition, a live-attenuated influenza vaccine (LAIV) is given as a nasal spray and can be used in healthy people aged 2 to 49 years who are not pregnant.
The seasonal influenza vaccine in recent years has been trivalent, with each component selected to protect against one of the 3 main groups of influenza viruses circulating in humans. A quadrivalent formulation of FluMist, manufactured by MedImmune, LLC, was licensed by the FDA for use in February 2012 in the United States. "It is anticipated that this formulation will replace the currently available seasonal trivalent LAIV formulation for the 2013–14 season," the CDC states on their Web site.