Cell-Cultured Influenza Vaccine Equivalent to Old-School Injection

Shortages of influenza vaccine due to a limited supply of chicken eggs may soon be a quaint memory of last year's H1N1 epidemic. The use of fertilized chicken eggs to cultivate the virus was a major bottleneck in vaccine production during 2009 (and particularly because the unusually fastidious, novel H1N1 required 2 eggs instead of the typical 1 to reach sufficient titers).

The use of cell-generated virus to mass produce vaccines is a top priority for the US government, and the European Union has already approved a cell-derived influenza vaccine, Novartis's Optaflu (way back in 2007). Ten months ago, Novartis opened its cell-cultured vaccine facility in Holly Springs, NC, the construction of which was supported by a big federal grant. Mass production of vaccine is expected in 2011 or 2012, according to the latest estimates from HHS Secretary Kathleen Sebelius.

But will the cell-produced vaccine be as efficacaious as the old-school injection? Confirming the EU's approval, the clinical answer appears to be yes. New results from a large, international placebo-controlled trial, conducted during the 2007-2008 flu season, showed that Optaflu was as efficacious and as well tolerated as Agrippal, Novartis's egg-based vaccine. And both inactivated vaccines were better at protecting against influenza than placebo.

Six-month efficacy against all circulating influenza virus strains were 69.5% and 63.0% for Optaflu and Agrippal, respectively, and the immunogenicity of both exceeded CBER's licensing criteria. The rates of confirmed influenza in subjects were 1.25% with Optaflu, 1.54% with Aggripal, and 3.96% with placebo—resulting in an approximately 70% risk reduction of infection with Optaflu vaccination.

The conclusion of the industry-sponsored study: "Both vaccines can be considered for annual influenza vaccination campaigns."

CBER = Center for Biologics Evaluation and Research.

HT: MedPage Today.