The first seasonal influenza vaccine grown in cultured mammalian cells instead of fertilized chicken eggs was approved last November by the US Food and Drug Administration. Flucelvax, manufactured by Novartis Vaccines and Diagnostics of Marburg, Germany, will use a cell culture technology, already employed for other vaccines. The advantages include the ability to satisfy demand during egg shortages or when particular viral strains prove difficult to grow. Additionally, making this vaccine in mammalian cells has the potential for faster startups when producers need to shift vaccine formulation to tackle abrupt changes in circulating flu strains, particularly at the onset of a pandemic. During the 2009 pandemic when a new H1N1 version of the influenza virus began circulating, for example, vaccine producers had difficulty maintaining supplies because the adapted H1N1 seed strain grew so slowly in eggs. Novartis will be ramping up its manufacturing capacity with a facility in Holly Springs, North Carolina. This plant was built with support from the federal Biomedical Advanced Research and Development Authority to expand vaccine production, including in the event of a public health emergency.