Viral vaccines are produced by viral infection of susceptible animal cells or by recombinant protein expression in suitable host cells. A variety of cell lines are used for production of viral vaccines, mostly cells derived from kidneys, such as Vero, MDCK, HEK293 and BHK-21, although others cell types can also be used (sf9, sf21, EB66®, ...). Specialty media offered in this category have been designed to allow maximum cell growth and infection.