title: Review of the Persistence of Herpes Zoster Vaccine Efficacy in Clinical Trials.
abstract: OBJECTIVE
  The live attenuated herpes zoster vaccine(*) was approved for the prevention of shingles in 2006. Initial Phase III clinical trials proved vaccine efficacy persisted during the study duration; however, assessment of long-term efficacy required additional studies. This article reviews efficacy data for the zoster vaccine that have been published since 2004. It focuses on studies assessing declining vaccine efficacy.
  
  
  METHODS
  MEDLINE, EMBASE, CENTRAL, and CINAHL databases were searched for zoster vaccine efficacy trials. Randomized controlled trials published from 2004 to 2015 were included in the review.
  
  
  RESULTS
  Six studies were included in the review. The zoster vaccine reduced the risk of herpes zoster by 51.3% to 72.4% in 2 Phase III trials. Primary and other analyses showed the vaccine was effective at reducing the burden of illness (61.1%), postherpetic neuralgia (66.5%), disease interference on functional status (66.2%), and disease impact on health-related quality of life (55%) compared with placebo. Surveillance studies showed a decrease in vaccine efficacy for reducing the incidence of herpes zoster during follow-up years 3.3 to 7.8 (39.6% relative reduction) and 4.7 to 11.6 (21.1% relative reduction).
  
  
  CONCLUSIONS
  Initial zoster vaccine efficacy is significant, but declines in post-vaccination years 3 to 11. This raises the question about the need for possible revaccination with the zoster vaccine. Clinicians should consider the declining efficacy when administering the zoster vaccine to patients. Future studies will need to address the impact of the varicella vaccine on the incidence of shingles and whether this impacts the efficacy of the zoster vaccine.
authors.affiliation: Pharmacy Practice Department, University of Charleston School of Pharmacy, Charleston, West Virginia. Electronic address: stephencook@ucwv.edu.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Cook
authors.affiliation: Department of Pharmaceutical and Administrative Sciences, University of Charleston School of Pharmacy, Charleston, West Virginia.
authors.forename: Dennis K
authors.initials: DK
authors.lastname: Flaherty
mesh_terms: D006562:Herpes Zoster / Q000517:prevention & control*; D053061:Herpes Zoster Vaccine / Q000008:administration & dosage*; D006801:Humans; D015994:Incidence; D051474:Neuralgia, Postherpetic / Q000517:prevention & control*; D011788:Quality of Life; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000008:administration & dosage
chemical_list: D053061:Herpes Zoster Vaccine; D014613:Vaccines, Attenuated
keywords: herpes zoster; shingles; vaccine