T Cell Responses to Varicella Zoster Virus (VZV)
With increasing age, immune responses to vaccination begin to decline. A decrease in vaccination success rates is already evident in the 6th and 7th decade of life. With the changing demographics of the US population, this decline in immune function is a major health concern.
The study of the immune responses to the naturally-acquired chicken pox virus and to the shingles vaccine will provide an important opportunity to learn more about the aging immune system and may lead to an improvement in vaccination strategies and identification of ways to improve vaccine responses in older individuals
|Study Design:||Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Prevention
|Official Title:||T Cell Responses to Varicella Zoster Virus After Vaccination and Viral Escape|
- To measure change in varicella zoster virus (VZV)-specific T cell frequencies [ Time Frame: Day 0 to Day 28 ]This will be measured by IFN-gamma ELISpot assay (a type of immunological assay)
- Measure antibody titers on day 28 [ Time Frame: Day 0 to Day 28 ]The antibody titers will be measured by IgG ELISA assay ( a type of immunological assay)
|Study Start Date:||June 2010|
|Estimated Study Completion Date:||December 2015|
|Estimated Primary Completion Date:||December 2014 (Final data collection date for primary outcome measure)|
Experimental: Zostavax™ vaccine group
Participants > 50 years will receive a single dose 0.65 ml Zostavax™ (live, attenuated zoster vaccine) administered by subcutaneous injection.
Other Name: Zoster Vaccine Live
No Intervention: Cross-sectional group
Participants 40-49 years of age will not receive any intervention
The objective of this protocol is to identify immune signatures that are associated with effective or poor vaccine responses to naturally-acquired herpes zoster virus and the zoster (shingles) vaccine, Zostavax.
The study is divided in 2 specific cohorts.
In the first cohort (cross-sectional study), the objective is to examine the influence of age and inherited factors on the varicella zoster virus (VZV)-specific immune response in those with a naturally-acquired VZV immunity (a prior history of chicken pox). Volunteers in this cohort will be identical twins and non-twins 40-49 years of age and will not be vaccinated with the licensed zoster vaccine. (Zostavax vaccine is approved only for individuals who are 50 years and above)
In the second cohort (vaccination study), healthy identical twin and non-twins who are 50 and above will be vaccinated with the licensed zoster vaccine, Zostavax. We will compare age-related and inherited vaccine responses focusing on factors that control the initiation of the T-cell immune response and T cell signatures at peak response that correlate with T cell memory development and antibody production. To assess VZV viremia, we will test for VZV by PCR at 5 study time points.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01911065
|United States, California|
|Stanford University School of Medicine|
|Stanford, California, United States, 94305|
|Principal Investigator:||Cornelia L Dekker, MD||Stanford University|
|Principal Investigator:||Jorg J Goronzy, MD, PhD||Stanford University|