Clinical Trial Details
— Status: Withdrawn
Administrative data
| NCT number |
NCT02026089 |
| Other study ID # |
13-1380 |
| Secondary ID |
|
| Status |
Withdrawn |
| Phase |
Phase 4
|
| First received |
|
| Last updated |
|
| Start date |
December 2021 |
| Est. completion date |
June 2022 |
Study information
| Verified date |
February 2021 |
| Source |
University of Colorado, Denver |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The purpose of the study is to learn more abou how the immune system responds to the
chickenpox vaccine in adults who had never had chickenpox as a child and were then vaccinated
as an adult. The study aims to learn more about the strength and duration of the protection
provided by the vaccine in adults, and to observe the immune response to an additional dose
of chickenpox vaccine in adults who had received the vaccine at least 5 years earlier. This
is especially relevant to workers in a hospital who may be exposed to chickenpox.
Description:
The population will be employees who were previously evaluated in the pre-employment phase by
the Occupational Health Clinic (OHC) of Colorado Children's Hospital (CHC) from 2004 until
2009 and were found to be seronegative for varicella antibody at that time and were thus
vaccinated per CHC protocol. Additionally, a matching number of comparator subjects who were
positive for varicella antibody at the pre-employment phase will be selected from the same
pool (2004-2009).
Subject participation will last up to 6 months. Subjects will be enrolled into one of two
study groups:
- Group 1 consisting of 50 subjects who tested seronegative for varicella antibody and
received varicella vaccine to meet employment criteria at least 5 years previously; and
- Group 2 consisting of 50 subjects who had natural varicella infection and thus tested
seropositive for varicella antibody at least 5 years previously.
Group 1 subjects will receive 1 additional dose (lifetime total will be 2 or 3) of varicella
vaccine (Varivax) and participate in a total of 4 study visits over a period of 6 months.
Before receiving the dose of varicella vaccine at Day 1, Group 1 subjects will be given the
CDC Vaccine Information Sheet for varicella vaccine. Study staff will review this with the
subject to assure understanding prior to administering vaccine. Vaccination will occur after
eligibility criteria have been confirmed and completion of a urine pregnancy test -with a
negative result - on females of childbearing potential. Following administration of the
varicella vaccine, the subject will be observed in the clinic for at least 15 minutes for
safety. Blood (60 ml per sample) will be collected from all Group 1 subjects on Day 1
immediately prior to vaccination, and at Day 7(±2), Day 30(±7) and Day 180(±14) in order to
measure VZV-specific antibody, antibody avidity, and cell-mediated immunity by the methods
indicated above. Subjects receiving a third lifetime dose of Varivax will be asked to
complete a diary for 5 days after vaccination to track anticipated and unanticipated
reactions to the vaccine.
Group 2 subjects, the comparator group, will receive no vaccine and will only participate in
the first visit for a blood draw. Blood (60 ml) will be collected from Group 2 participants
only at Day 1. Subject information to be recorded includes age; gender; varicella vaccine
history at the OHC; age vaccinated (calculate interval since vaccination); the number of
doses (1 vs 2) received; and any exposure to varicella or HZ (including involvement in any
CHC outbreak work-up).
