A Variant Allele in Varicella-Zoster Virus Glycoprotein B Selected during Production of the Varicella Vaccine Contributes to Its Attenuation.

ABSTRACT: Attenuation of the live varicella Oka vaccine (vOka) has been attributed to mutations in the genome acquired during cell culture passage of pOka (parent strain); however, the precise mechanisms of attenuation remain unknown. Comparative sequence analyses of several vaccine batches showed that over 100 single-nucleotide polymorphisms (SNPs) are conserved across all vaccine batches; 6 SNPs are nearly fixed, suggesting that these SNPs are responsible for attenuation. By contrast, prior analysis of chimeric vOka and pOka recombinants indicates that loci other than these six SNPs contribute to attenuation. Here, we report that pOka consists of a heterogenous population of virus sequences with two nearly equally represented bases, guanine (G) or adenine (A), at nucleotide 2096 of the ORF31 codin

SUBMITTER: Sadaoka T 

PROVIDER: S-EPMC9426484 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature