Safety and immunogenicity profile of the concomitant administration of ZOSTAVAX and inactivated influenza vaccine in adults aged 50 and older

J Am Geriatr Soc. 2007 Oct;55(10):1499-507. doi: 10.1111/j.1532-5415.2007.01397.x.


Objectives: To evaluate the safety and immunogenicity of ZOSTAVAX administered concomitantly with inactivated influenza vaccine or sequentially in adults aged 50 and older.

Design: Randomized, blinded, placebo-controlled study.

Setting: Thirteen U.S. and seven European study sites.

Participants: Three hundred eighty-two concomitantly, 380 sequentially vaccinated subjects.

Intervention: The concomitant vaccination group received influenza vaccine and ZOSTAVAX at separate injection sites on Day 1 and placebo at Week 4. The nonconcomitant vaccination group received influenza vaccine and placebo at separate injection sites on Day 1 and ZOSTAVAX at Week 4.

Measurements: Primary safety endpoints: vaccine-related serious adverse experiences (AEs) within 28 days postvaccination (PV); and diary card-prompted local and systemic AEs. Primary immunogenicity endpoints: geometric mean titer (GMT) and geometric mean fold rise (GMFR) from baseline of varicella-zoster virus (VZV) antibody (Ab) at 4 weeks PV according to glycoprotein enzyme-linked immunosorbent assay (gpELISA) and GMT of influenza Ab for the three vaccine strains (2005-2006 influenza season) at 4 weeks PV according to hemagglutination inhibition assay. Secondary immunogenicity endpoint: influenza seroconversion rates (SCRs).

Results: No serious AEs related to ZOSTAVAX were observed during the study. VZV Ab GMTs 4 weeks PV for the concomitant and sequential groups were 554 and 597 gpELISA U/mL, respectively. The estimated VZV Ab GMT ratio was 0.9 (95% confidence interval (CI)=0.8-1.0), indicating noninferior (P<.001 for the null hypothesis of GMT ratio <0.67) responses. Estimated VZV Ab GMFR from baseline in the concomitant group was 2.1 (95% CI=2.0-2.3), indicating acceptable fold rise. Estimated GMT ratios (concomitant/sequential) for influenza strains A(H1N1), A(H3N2), and B were 0.9 (95% CI=0.8-1.1), 1.1 (95% CI=0.9-1.3), and 0.9 (95% CI=0.8-1.1), respectively, and SCRs were comparable across both groups, with more than 85% achieving titers of 1:40 or greater, meeting regulatory criteria.

Conclusion: ZOSTAVAX and influenza vaccine given concomitantly are generally well tolerated in adults aged 50 and older. Ab responses were similar whether ZOSTAVAX and influenza vaccine were given concomitantly or sequentially.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Bacterial / blood
  • Antibodies, Viral / blood
  • Drug Administration Schedule
  • Endpoint Determination / methods
  • Female
  • Herpes Zoster Vaccine / administration & dosage
  • Herpes Zoster Vaccine / adverse effects*
  • Herpes Zoster Vaccine / immunology
  • Humans
  • Influenza A Virus, H1N1 Subtype / immunology
  • Influenza A Virus, H3N2 Subtype / immunology
  • Influenza B virus / immunology
  • Influenza Vaccines / administration & dosage
  • Influenza Vaccines / adverse effects*
  • Influenza Vaccines / immunology
  • Male
  • Middle Aged


  • Antibodies, Bacterial
  • Antibodies, Viral
  • Herpes Zoster Vaccine
  • Influenza Vaccines