FDA has issued a final guidance entitled “Guidance for Industry: Characterization and Qualification of Cell Substrates and Other Biological Materials Used in the Production of Viral Vaccines for Infectious Disease Indications.” The guidance is intended to boost the efforts towards the development safe and effective cell-based viral vaccines to address emerging and pandemic threats. In order to boost the development of vaccines grown in cells (rather than other mediums, such as chicken eggs), the guidance seeks to provide information on the characterization and qualification of cell substrates, viral seeds, and other biological materials used for the production of viral vaccines for human use. FDA states that the guidance is intended to supplement the recommendations on the production of viral vaccines for the prevention and treatment of infectious diseases found in the International Conference on Harmonization (ICH) documents Q5A and Q5.