Molecular Analysis of Varicella Vaccines and Varicella-Zoster Virus from Vaccine-Related Skin Lesions

Abstract

To prevent complications that might follow an infection with varicella-zoster virus (VZV), the live attenuated Oka strain (V-Oka) is administered to children in many developed countries. Three vaccine brands (Varivax from Sanofi Pasteur MSD; Varilrix and Priorix-Tetra, both from Glaxo-Smith-Kline) are licensed in Germany and have been associated with both different degrees of vaccine effectiveness and adverse effects. To identify genetic variants in the vaccines that might contribute to rash-associated syndromes, single nucleotide polymorphism (SNP) profiles of variants from the three vaccines and rash-associated vaccine-type VZV from German vaccinees were quantitatively compared by PCR-based pyrosequencing (PSQ). The Varivax vaccine contained an estimated 3-fold higher diversity of VZV variants, with 20% more wild-type (wt) SNPs than Varilrix and Priorix-Tetra. These minor VZV variants in the vaccines were identified by analyzing cloned full-length open reading frame (ORF) orf62 sequences by chain termination sequencing and PSQ. Some of these sequences amplified from vaccine VZV were very similar or identical to those of the rash-associated vaccine-type VZV from vaccinees and were almost exclusively detected in Varivax. Therefore, minorities of rash-associated VZV variants are present in varicella vaccine formulations, and it can be concluded that the analysis of a core set of four SNPs is required as a minimum for a firm diagnostic differentiation of vaccine-type VZV from wt VZV.The varicella-zoster virus (VZV) live attenuated Oka strain (V-Oka) is licensed in developed countries for vaccination against varicella. In Germany, routine vaccination of healthy children Ͼ11 months of age has been performed since 2004. Since then, varicella morbidity has declined (16). The mixtures of V-Oka strains with different single nucleotide polymorphism (SNP) profiles present in vaccine preparations and the reported genomic variation of vaccine VZV strains have prompted investigations of the linkage of certain genomic variants to episodes of vaccine-induced rash (9, 10).We aimed at comparing the SNP profiles of the varicella vaccines used in Germany and of vaccine-type VZV from German vaccinees for several reasons. First, three vaccine brands are distributed in Germany (Varivax from Sanofi Pasteur MSD [SPMSD], Leimen, Germany; Varilrix and PriorixTetra, both from GlaxoSmithKline [GSK], Munich, Germany) and have been associated with different degrees of vaccine effectiveness (17). In addition, data from the German varicella sentinel (16) indicated that the vaccines might be related to different frequencies of rash-associated syndromes, i.e., mild forms of varicella or zoster (Anette Siedler and Bernhard Ehlers, unpublished data). Second, vaccine-type VZV strains causing rash-associated clinical syndromes in vaccinees have been reported to contain a number of wild-type (wt) SNPs. It has been hypothesized that these vaccine-type, wt SNP-containing VZV strains are minor components of the vaccines (1, 9, 10, 13). To substantiate t...

Clinical and molecular aspects of the live attenuated Oka varicella vaccine

“…Some studies have reported that vOka genotypes in rash vesicles are monomorphic but that different vesicles in the same individual harbor different genotypes . Others have found that individual vesicles contain multiple genotypes . Despite the discrepancies, these findings highlight that rashes are not caused by a single vOka haplotype from the vaccine.…”

“…Over 90% of these were present on less than 10% of genomes and would therefore have been missed by traditional Sanger methods used for previous whole‐genome sequencing of vOka preparations . In addition to differences in the sequence of the three commercial vaccine preparations, variation has also been reported in the genetic composition of Varilrix when compared with Varivax (Table ). There is evidence to suggest that such differences affect immunogenicity of the vaccines.…”

“… —, not analyzed; sequence of lots A and 1 are derived from ; sequence of lot B is derived from ; sequence of lots C and 2 are derived from ; sequence of lots 3 and 4 are derived from . Cells in bold indicate positions where the same allele profile is present in all lots of Varivax, Varilrix or both vaccine preparations.…”

Die Varizellenimpfung in Deutschland

“…Die Wirksamkeit nach 1 Impfung wurde dabei auch impfstoffspezifisch in Ausbrüchen untersucht, wobei sich Hinweise auf Unterschiede zwischen den in Deutschland verwendeten Impfstoffen ergaben [19]. Diese Ergebnisse korrespondierten mit der bei der Nukleinsäuren-Sequenzanalyse gefundenen genetischen Mikroheterogenität der Impfviren der in Deutschland verwendeten Varizellenlebendimpfstoffe [29,30]. Weitere Untersuchungen sind jedoch nötig, um die klinische Relevanz dieser Ergebnisse genauer zu bestimmen und um die impfstoffspezifische Wirksamkeit von 2 Impfungen im Ausbruchsfall zu ermitteln.…”

Microbiology laboratory and the management of mother-child varicella-zoster virus infection

“…They are more sensitive than viral cultures, DFA and Tzanck smears particularly when primers for genes 28 and 29 are used [30,428,429,440,449,450,457] . Molecular biology tests are also useful in the case of varicella appearing 7-42 d after vaccination, in the case of herpes zoster appearing 42 d after vaccination and, in the case of the suspected transmission of the vaccine virus, can distinguish virus vaccine, wild-type virus and potential recombinants of vaccine and wild-type viruses [30,451,452,454,455,[458][459][460][461][462][463] , although some tests have proved to be less appropriate over time for these purposes [30] . There are also some multiplex assays that can differentiate HSV-1, HSV-2 and VZV in cutaneous and mucocutaneous samples, making them very useful in the case of skin lesions of unclear etiology or immunosuppressed patients [429,464,465] .…”