title: Modeling the durability of ZOSTAVAX® vaccine efficacy in people ≥60 years of age.
abstract: Since 2006, the vaccine, ZOSTAVAX(®), has been licensed to prevent herpes zoster. Only limited clinical follow-up data are available to evaluate duration of protection, an important consideration when developing HZ vaccination policy recommendations. Four Poisson regression models were developed based on an integrated analysis of data from the Shingles Prevention Study and its Short Term Persistence extension to estimate the effects of years-since-vaccination and chronological-age on vaccine efficacy among people ≥60 years old. The models included number of HZ cases parsed into categories by chronological-age and time-since-vaccination as the dependent variable with different explanatory variables in each model. In all models, the interaction between vaccine-group and chronological-age was statistically significant indicating that vaccine efficacy decreases with the expected effects of advancing age but the interaction between vaccine-group and time-since-vaccination was not statistically significant indicating that much of the reduction in vaccine efficacy over time-since-vaccination can be explained by increasing age.
authors.affiliation: Merck & Co., Inc., Kennelworth, NJ, United States.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Veterans Affairs Cooperative Studies Program Coordinating Center, West Haven, CT, United States.
authors.forename: Jane H
authors.initials: JH
authors.lastname: Zhang
authors.affiliation: University of Rochester, Rochester, NY, United States.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Betts
authors.affiliation: Minneapolis VAMC and University of Minnesota, Minneapolis, MN, United States.
authors.forename: Vicki A
authors.initials: VA
authors.lastname: Morrison
authors.affiliation: Merck & Co., Inc., Kennelworth, NJ, United States.
authors.forename: Ruifeng
authors.initials: R
authors.lastname: Xu
authors.affiliation: Merck & Co., Inc., Kennelworth, NJ, United States.
authors.forename: Robbin F
authors.initials: RF
authors.lastname: Itzler
authors.affiliation: Merck & Co., Inc., Kennelworth, NJ, United States.
authors.forename: Camilo J
authors.initials: CJ
authors.lastname: Acosta
authors.affiliation: Merck & Co., Inc., Kennelworth, NJ, United States.
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Dasbach
authors.affiliation: Merck & Co., Inc., Kennelworth, NJ, United States.
authors.forename: James M
authors.initials: JM
authors.lastname: Pellissier
authors.affiliation: Department of Veterans Affairs Cooperative Studies Program Coordinating Center, West Haven, CT, United States.
authors.forename: Gary R
authors.initials: GR
authors.lastname: Johnson
authors.affiliation: Merck & Co., Inc., Kennelworth, NJ, United States. Electronic address: ivan_chan@merck.com.
authors.forename: Ivan S F
authors.initials: IS
authors.lastname: Chan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D005260:Female; D006562:Herpes Zoster / Q000517:prevention & control*; D053061:Herpes Zoster Vaccine / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016012:Poisson Distribution; D012044:Regression Analysis; D013997:Time Factors; D014611:Vaccination; D064166:Vaccine Potency
chemical_list: D053061:Herpes Zoster Vaccine
keywords: Concurrent age effect; Durability; Herpes zoster; Poisson regression; Time effect; Vaccine efficacy; Zoster vaccine