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Not yet recruiting NCT06482216

Correlation of Protection Against Varicella in an Exploratory Study

— Observational Varicella

For patients and families

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An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Varicella vaccine.
Who it may be relevant to
Registry conditions: Varicella. Basic parameters: 1 year — 12 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
Center list to be confirmed — check the primary protocol.
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

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Overview

This study consists of two parts. Part 1 is a retrospective cohort study and part 2 is a prospective cohort study. In Part 1 ,the scaled logit model was used to assess the correlation between varicella-zoster virus (VZV) antibody titers using fluorescent-antibody-to-membrane-antigen assay (FAMA) 30 days after varicella vaccine immunization and the risk of subsequent varicella breakout/disease , to determine the protective threshold for achieving FAMA antibodies. Part 2 was to validate the model in part 1.

Detailed description

Part 1 was based on a previous Phase Ⅲ, randomized, placebo-controlled clinical trial (NCT02981836) conducted from 2016 to 2017. The analysis data of part 1 was from historical serum, historical varicella cases and additional one year case monitoring conducted as an extension of the Phase III study.

Part 2 was conducted based on close contacts of varicella cases. All close contacts without varicella symptoms will be recruited and followed up for 14 days to monitor the occurrence of the varicella cases. Part 2 aimed to compare the differences of FAMA antibody titers in varicella breakthrough cases, non-breakthrough cases, and non-cases at the time of exposure to validate/calibrate the model established in part 1.

Interventions

  • Biological Varicella vaccine
    lyophilized powder,subcutaneous injection

Primary outcome measures

  • Retrospective cohort: Varicella confirmed case [Time frame: one year after enrollment]
  • Retrospective cohort: Varicella antibody titer [Time frame: on Day 30 after vaccination]
  • Prospective cohort: Varicella confirmed case [Time frame: Within 14 days after enrollment]
  • Prospective cohort: Varicella antibody titer [Time frame: Enrollment]
Secondary outcome measures (2)
  • Prospective cohort: Varicella antibody titer [Time frame: Within 3 days after eruption]
  • Prospective cohort: Varicella antibody titer [Time frame: Within 14-21 days after eruption]

Eligibility criteria

Inclusion criteria

  • 1-12 years children who were the siblings or children of the indicator varicella cases, or the deskmates/roommates of the indicator varicella cases;
  • Having close contacts with the indicator varicella cases at least 2 days during the period from 5 days before the onset and 2 days after the onset;
  • Without varicella vaccination history or having varicella vaccination history (the last dose of varicella was manufacured by Sinovac, with an interval of >30 days before enrollment)
  • Subjects/legal guardian can understand and sign the informed consent;
  • Being able to provide legal proof of identity.

Exclusion criteria

  • Without varicella history;
  • Body temperature ≥37.0℃ on the day of enrollment, or skin rash on the head, torso, and limbs;
  • Having any confirmed or suspected immunodeficiency disorder, including tumor patients undergoing chemotherapy, human immunodeficiency virus (HIV) infection, continuous use of steroid hormones for more than 30 days (prednisone equivalent ≥2mg/kg days in children), or having other immunosuppressive disorder as determined by the clinician;
  • The investigators considered that participation in this study was not appropriate for various other reasons.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Observational model
Cohort

Study locations

Center list to be confirmed — check the primary protocol.

Identifiers

NCT: NCT06482216 · PRO-VZV-4007

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗