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Parvoviruses: A Future Challenge?. Nicola Boschetti, ZLB Behring AG, Bern. Emerging Viruses. Definition:. “Viruses that have newly appeared in a population or have existed previously but are rapidly increasing in incidence or geographic range.” Morse, S.S. (1995), Emerg Infect Dis 1 , 7-15
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Parvoviruses: A Future Challenge? Nicola Boschetti, ZLB Behring AG, Bern
Emerging Viruses Definition: “Viruses that have newly appeared in a population or have existed previously but are rapidly increasing in incidence or geographic range.” Morse, S.S. (1995), Emerg Infect Dis 1, 7-15 ... and those which previously existed but come into our awareness as etiological agent of some disease.
Emerging Viruses Virus Environment Host Viruses depend on favorable hosts in a favorable environment.
Carnivore Parvoviruses FPV: Feline ParvovirusRPV: Raccoon ParvovirusMEV: Mink Enteritis VirusBFPB: Blue Fox Parvovirus Parrish CR, ASM News (1997) 63, 307
Carnivore Parvoviruses source: Institute for Molecular Virology (Wisconsin) The emergent canine parvoviruses are characterized by specific amino acid changes in and around a raised region of the capsid termed the threefold spike. Structural and mutational studies suggest that this region binds the cellular transferrin receptor and controls host range.
Sequence Variability Sequence variability of human erythroviruses at threefold symmetry axis.
Recently discovered Parvoviruses PNAS (2005) 102, 12891 PNAS (2001), 98, 11609 • BPV2 &BPV3 • humanBocavirus • PARV4
Virus safety of biological / biotechnological products Potential Viral Contamination Approaches (Prevention & Elimination) Biological Source Material Selection Testing Contaminated Raw Materials Elimination Adventitiously introduced in manufacturing cGMP
Virus elimination mechanisms ± ± Rough classification of viruses: ± ? ? ? ? Virus elimination principles used in manufacturing: Partitioning Inactivation: S/D, Caprylate Pasteurization, low pH Virusfiltration
Conclusion • (Parvo) viruses are evolving. • Novel (parvo) viruses are/will be discovered. • Current Biologicals have a high safety standard basing on four complementary approaches. • Proactive investigations on (small non-enveloped) viruses in order to discover such viruses entering the source and raw materials should continue.