An overview of viral and viral-like agents in cell culture systems

The first recognition of seriously contaminated biological products occurre d almost 100 years ago. More recently, in the second half of this century, the potential for contamination by viral and viral-like agents became obvio us when the SV-40 virus was identified as an endogenous agent in the cell c ultures used to produce polio vaccines. The history of major contamination incidents is reviewed, and current issues are discussed.