1928. Effectiveness of Live Zoster Vaccine in Preventing Herpes Zoster
Session: Poster Abstract Session: Vaccines: Varicella/Zoster
Saturday, October 10, 2015
Room: Poster Hall
Posters
  • 1928_IDWPoster.pdf (183.9 kB)
  • Background: Zostavax™, a live zoster vaccine, was licensed in the U.S. in 2006 for the prevention of herpes zoster (HZ) in people over 60 (60+) years, and extended to those 50 and older in 2011. We assessed vaccine effectiveness (VE) over 5 years following immunization. 

    Methods: The study is conducted at Kaiser Permanente Northern California (KPNC). The study design is an open cohort; KPNC members enter the study when they become age-eligible for the vaccine.  Incident HZ is defined as a new HZ episode without evidence of HZ in the prior year.  This preliminary analysis included HZ cases identified by having a diagnosis code of HZ with an antiviral prescription or a positive  varicella viral test. VE by time since vaccination was estimated using Cox regression adjusted for sex, age, race/ethnicity, and several time-varying variables, including healthcare use, comorbid conditions and immune-compromise status.  A variable was included in the model for each year since vaccination; risk sets were anchored to a calendar timeline.  Average VE at 5 years was calculated as a weighted average of annual VE.

    Results: From 2007 through 2013, a total of 303,828 of the ~1.3 million study participants received one dose of Zostavax, with 23,477 of those participants vaccinated at age 50-59.  As of 2013, vaccine coverage was >40% in 60+ but only 4% in 50-59.  In all age groups (50-59, 60-69, 70-79 and 80+ years at the time of vaccination), VE in preventing HZ was >60% during the 1st year following vaccination (70%, 73%, 65% and 64%, respectively), and decreased in the following years.  For all ages combined, VE was 69% (95% CI 66% -71%) during the first year after immunization, then fell to 45% (42%-49%), 38% (33%-42%), 41% (36%-42%), and 38% (#2%-44%) in years 2, 3, 4, and 5, respectively.  Overall, the average VE in preventing HZ over 5 years of follow-up was 50% (95%CI, 47%-52%), 45% (41%-48%) and 45% (38%-50%) among individuals vaccinated at 60-69, 70-79, and 80+ years, respectively.  In 50-59, average VE was 62% over 3 years.

    Conclusion: We found effectiveness of live zoster vaccine in routine use to be 69% during year one, with evidence of waning after that.  Average VE of a single dose over 5 years following routine vaccination was between 45%-50% among people 60+.

    Roger Baxter, MD, FIDSA1, Joan Bartlett, MPH, MPP1, Bruce Fireman, MA1, Morgan Marks, PhD2, John Hansen, MPH1, Ned Lewis, MPH1, Laurie Aukes, RN1, Yong Chen, PhD, MHS2 and Patricia Saddier, MD, PhD2, (1)Kaiser Permanente Vaccine Study Center, Oakland, CA, (2)Merck & Co., Inc. Pharmacoepidemiology Department, North Wales, PA

    Disclosures:

    R. Baxter, Merck: Grant Investigator , Research grant
    GSK: Grant Investigator , Research grant
    Pfizer: Grant Investigator , Research grant
    Sanofi Pasteur: Grant Investigator , Research grant

    J. Bartlett, None

    B. Fireman, None

    M. Marks, Merck Sharp & Dohme, Inc.: Employee and Shareholder , Salary

    J. Hansen, None

    N. Lewis, None

    L. Aukes, None

    Y. Chen, Merck & Co., Inc.: Employee and Shareholder , Salary

    P. Saddier, Merck Sharp & Dohme, Corp.: Employee and Shareholder , Salary

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.