title: Cost-effectiveness of a vaccine to prevent herpes zoster and postherpetic neuralgia in older adults.
abstract: BACKGROUND
  The Shingles Prevention Study showed that a varicella-zoster virus (VZV) vaccine administered to adults 60 years of age or older reduced the incidence of herpes zoster from 11.12 to 5.42 cases per 1000 person-years. Median follow-up was 3.1 years, and relative risk reduction was 51.3% (95% CI, 44.2% to 57.6%).
  
  
  OBJECTIVE
  To assess the extent to which clinical and cost variables influence the cost-effectiveness of VZV vaccination for preventing herpes zoster in immunocompetent older adults.
  
  
  METHODS
  Decision theoretical model.
  
  
  METHODS
  English-language data published to March 2006 identified from MEDLINE on herpes zoster rates, vaccine effectiveness, quality of life, medical resource use, and unit costs.
  
  
  METHODS
  Immunocompetent adults 60 years of age or older with a history of VZV infection.
  
  
  METHODS
  Lifetime.
  
  
  CONCLUSIONS
  U.S. societal.
  
  
  METHODS
  Varicella-zoster virus vaccination versus no vaccination.
  
  
  METHODS
  Incremental quality-adjusted survival and cost per quality-adjusted life-year (QALY) gained.
  
  
  RESULTS
  By reducing incidence and severity of herpes zoster, vaccination can increase quality-adjusted survival by 0.6 day compared with no vaccination. One scenario in which vaccination costs less than 100,000 dollars per QALY gained is when 1) the unit cost of vaccination is less than 200 dollars, 2) the age at vaccination is less than 70 years, and 3) the duration of vaccine efficacy is more than 30 years.
  
  
  RESULTS
  Vaccination would be more cost-effective in "younger" older adults (age 60 to 64 years) than in "older" older adults (age > or =80 years). Longer life expectancy and a higher level of vaccine efficacy offset a lower risk for herpes zoster in the younger group. Other factors influencing cost-effectiveness include quality-of-life adjustments for acute zoster, unit cost of the vaccine, risk for herpes zoster, and duration of vaccine efficacy.
  
  
  CONCLUSIONS
  The effectiveness of VZV vaccination remains uncertain beyond the median 3.1-year duration of follow-up in the Shingles Prevention Study.
  
  
  CONCLUSIONS
  Varicella-zoster virus vaccination to prevent herpes zoster in older adults would increase QALYs compared with no vaccination. Resolution of uncertainties about the average quality-of-life effects of acute zoster and the duration of vaccine efficacy is needed to better determine the cost-effectiveness of zoster vaccination in older adults.
authors.affiliation: SPHERE Institute and Acumen LLC, Burlingame, California 94010, USA. jhornberger@acumen-llc.com
authors.forename: John
authors.initials: J
authors.lastname: Hornberger
authors.forename: Katherine
authors.initials: K
authors.lastname: Robertus
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003198:Computer Simulation; D017281:Cost of Illness; D003362:Cost-Benefit Analysis; D003662:Decision Theory; D005260:Female; D006562:Herpes Zoster / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D014645:Herpesvirus 3, Human / Q000276:immunology*; D022283:Herpesvirus Vaccines / Q000191:economics* / Q000627:therapeutic use; D006801:Humans; D007121:Immunocompetence; D015994:Incidence; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D051474:Neuralgia, Postherpetic / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D019057:Quality-Adjusted Life Years; D012680:Sensitivity and Specificity
chemical_list: D022283:Herpesvirus Vaccines