Persistence of immune response to an adjuvanted varicella-zoster virus subunit vaccine for up to year nine in older adults.

ABSTRACT: BACKGROUND:In adults aged ?60 years, two doses of the herpes zoster subunit vaccine (HZ/su; 50 µg varicella-zoster virus glycoprotein E [gE] and AS01B Adjuvant System) elicited humoral and cell-mediated immune responses persisting for at least six years. We assessed immunogenicity nine years post-initial vaccination. METHODS:This open extension study (NCT02735915) followed 70 participants who received two HZ/su doses in the initial trial (NCT00434577). Blood samples to assess the cellular (intracellular cytokine staining) and humoral (ELISA) immunity were taken at year nine post-initial vaccination. RESULTS:Participants' mean age at dose 1 was 72.3 years. The fold increases over pre-vaccination in the mean frequency of gE-specific CD4+ T-cells expressing ?2 activation markers plateaued from year four post-dose 1 until year nine. Anti-gE antibody geometric mean concentrations plateaued and remained above pre-vaccination levels from year four onwards. Immunogenicity at year nine was similar across age strata (60-69, ?70 years) and confirmed statistical prediction model results using data for up to year six. Further modeling using all data up to year nine predicted immune responses would remain above the pre-vaccination level up to year 15. CONCLUSION:In adults aged ?60 years, HZ/su-induced immunogenicity remained above pre-vaccination levels for at least nine years post-initial vaccination. SUMMARY:After vaccination with HZ/su, both cell mediated and humoral immunity remained above pre-vaccination levels up to year 9 regardless of age group. Immune responses are predicted to remain above baseline up to 15 years post initial vaccination.

SUBMITTER: Schwarz TF 

PROVIDER: S-EPMC6037441 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature