"Production capacity is another limitation to deployment of pandemic influenza vaccine. Current global capacity for pandemic influenza vaccine production is less than 3 billion doses per year, far short of the 7 billion doses that would be needed for universal coverage. To address some of these problems with egg-based vaccine production, some pharmaceutical companies are attempting to eliminate eggs from the process altogether. Novartis produces influenza vaccine from virus cultivated in cells derived from canine kidney cells (see the FDA information on this vaccine). Protein Sciences Corporation produces influenza vaccine using recombinant DNA technology and an insect virus system (see the FDA information). Other companies are developing influenza vaccine produced from different types of cell lines. Given that it takes roughly the same amount of time for influenza virus to replicate in eggs and in cell culture, shifting to cell culture will not necessarily speed up this phase of production. However, using cell culture technology will eliminate the lead time necessary to secure fertilized eggs for vaccine production and will reduce some of the variables related to the quantity of vaccine virus achieved with eggs. Additionally, egg-based influenza vaccine production requires a step in which the influenza virus is altered so that it reproduces well in eggs. If cell-based manufacturers can skip that step, they can begin vaccine production 4-6 weeks earlier than egg-based manufacturers."