Sequencing and characterization of Varicella-Zoster virus vaccine strain SuduVax
1 Department of Microbiology, Chungbuk National University, Cheongju, South Korea
2 Department of Micorbiology, College of Medicine, Yeungnam University, Daegu, South Korea
3 Mogam Biotechnology Research Institute, Yongin, South Korea
4 Green Cross Company, Yongin, South Korea
5 Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, South Korea
6 Department of Computer Science, Chungbuk National University, Cheongju, South Korea
Virology Journal 2011, 8:547 doi:10.1186/1743-422X-8-547Published: 16 December 2011
Varicella-zoster virus (VZV) causes chickenpox in children and shingles in older people. Currently, live attenuated vaccines based on the Oka strain are available worldwide. In Korea, an attenuated VZV vaccine has been developed from a Korean isolate and has been commercially available since 1994. Despite this long history of use, the mechanism for the attenuation of the vaccine strain is still elusive. We attempted to understand the molecular basis of attenuation mechanism by full genome sequencing and comparative genomic analyses of the Korean vaccine strain SuduVax.
SuduVax was found to contain a genome that was 124,759 bp and possessed 74 open reading frames (ORFs). SuduVax was genetically most close to Oka strains and these Korean-Japanese strains formed a strong clade in phylogenetic trees. SuduVax, similar to the Oka vaccine strains, underwent T- > C substitution at the stop codon of ORF0, resulting in a read-through mutation to code for an extended form of ORF0 protein. SuduVax also shared certain deletion and insertion mutations in ORFs 17, 29, 56 and 60 with Oka vaccine strains and some clinical strains.
The Korean VZV vaccine strain SuduVax is genetically similar to the Oka vaccine strains. Further comparative genomic and bioinformatics analyses will help to elucidate the molecular basis of the attenuation of the VZV vaccine strains.