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Genetic differences between VZV wild-type and Oka strains Judith Breuer Professor of Virology St Barts and The London Hospital Medical School UK 1 Rome, Italy - March 18, 2005 masque....
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Oka vaccine Live attentuated virus
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A B C Bang + Bang BAN7 Reproduced from Barrett-Muir W, et al. J Virol 2002;76:1971-9 with permission from the American Society for Microbiology J 95
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Bang + Bang BAN7 Loparev VN, et al. J Virol 2004;78: 8349-58. E M J 95
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Bang + Bang BAN7 Grose, J clin Virol 2005; in press E A 95
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pOka vs Dumas 1/700 MSP vs Dumas 1/2000 BC vs Dumas 1/2000 BC vs MSP 1/2700 Glycoproteins 5,14, 31, 37, 50, 60, 67 68 6 (8)745(1) transcriptional 4,10 21 61,62,63,64 6011 (42) replication 6, 8, 16, 18, 19, 28,29, 48,51,52,55,59 14 (18)12 (2)1 Kinases proteases 33,36, 47, 66 3 (2)100 Tegument 11, 12,, 22, 54 9 (19)344(1)
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pOka vs Dumas 1/700 MSP vs Dumas 1/2000 BC vs Dumas 1/2000 BC vs MSP 1/2700 pOka vs vOka- 1 in 2-3000 Glycoproteins 5,14, 31, 37, 50, 60, 67 68 6 (8)965(1)3(2) transcriptional 4,10 21 61,62,63,64 6011 (42)10 (8) replication 6, 8, 16, 18, 19, 28,29, 48,51,52,55,59 14 (18)11 (2)16 (1) Kinases proteases 33,36, 47, 66 3 (2)0000 (1) Tegument 11, 12,, 22, 54 9 (19)344(1)2 (1)
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Which are the genetic correlates of vaccine attenuation?
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Reduced ability of vOka to spread from T-cells to melanoma cell lines (Soong et al, 2000) Similar to ORF 47 mutant Evidence that ORF 47 p may be a virulence factor Soong W, et al. J Virol. 2000;74:1864-70.
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Vaccine preparations in comparison to pOka
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Fig. 1. Gel electrophoresis of polymerase chain reaction (PCR) products. A: Amplification across BssHII site in ORF 62 and restriction enzyme digest. Lane 1: Parental Oka virus; lane 2, UK wild type J virus; lane 3, Oka Merck vaccine; lanes 4 – 6, vaccine zoster viruses;lanes 7 – 18, vaccine rash viruses; lane 19, molecular weight marker (band sizes 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 kb).B: Amplification across Alu1 site in ORF 6 and restriction digest. Lane 1: 100 bp molecular weight marker; lane 2, parental Oka virus; lane 3, UK wild type J virus; lane 4, Oka Merck vaccine; lanes 5 – 7, vaccine zoster viruses; lanes 8 – 19, vaccine rash viruses; lane 20, 100 bp molecular weight marker.
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Which mutations are important for attenuation?
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Vaccine preparations in comparison to pOka Is IE62 necessary for attenuation ?
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Does the vaccine protect against wild type viruses? IE 62. Overlapping peptide pools CD8 + cells assayed by Ifn staining Peptide pool 5 recognised by A2 restricted PBLs
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Conclusion 1.wtVZV varies geographically, and between related strains 2.vOka vaccine is attenuated biologically and clinically 3.The vOka vaccine is made up of a mixture of strains 4.Attenuation is likely to be multigenic and involve ORFs 30-54 5.vOka immune protection may be enhanced by the mixture of wt and vaccine mutations in the vaccine preparation.
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