COLD ADAPTED VIRAL ATTENUATION (CAVA) AND NOVEL ATTENUATED POLIOVIRUS STRAINS

摘要

A poliovirus (PV) strain was attenuated by a novel method of Cold Adapted Viral Attenuation (CAVA). The resulting recombinant attenuated PV CAVA PV shows wild type replication at 30°C but no substantial replication at 37°C. The inability to replicate at 37°C is defined by an inability to quantify virus during infection at this temperture by titration (infectious units) qPCR (viral RNA) or Electron Microscopy (visual signs of infection). CAVA PV is genetically stable under production conditions and shows utility for use as the backbone to produce attenuated strains with the same antigenic profile as conventional vaccines by replacing the sequence coding for the capsid of CAVA PV with sequences coding for capsids of different PV strains. Furthermore mutations identified in CAVA PV can be engineered into different even wild type and neurovirulent poliovirus background strains to obtain additional CAVA PV strains.