Challenges for Current Assays for Adventitious Virus Detection
| • Unknown viruses and latent viruses in novel cell substrates (viral vaccines) |
| – Oncogenic viruses in tumorigenic mammalian and avian cell lines and in tumor-derived mammalian cell |
| – Exogenous and endogenous viruses in stem cell lines |
| – Recombinant viruses from genetically engineered cells |
| – Viruses in cell lines derived from insects, plants, and bacteria |
| • Unexpected viruses in viral-vectored products |
| – Generation of novel replication-competent viruses |
| – Co-packaging of unknown “unwanted” RNAs and DNAs |
| • Discovery of novel viruses |
| – In human infections: human polyomaviruses (MCV), retroviruses (SFV), arboviruses (WNV) |
| – In products: porcine circovirus in rotavirus vaccines; vesivirus 2117 in some CHO cell products (Cerezyme and Fabrazyme) |