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NCT Number: NCT06776692

Characterisation of Dengue Vaccine-induced Specific Immunity in Vaccinees With and Without Prior Exposure to Flavivirus Infections or Vaccination

The goal of this observational study is to learn about the immunity induced by the Qdenga® vaccine in vaccinees.

Participants that will receive the Dengue vaccine as part of their routine before a travel will be asked to undergo a blood sample at the time of administration of the first dose (T0), 24-48 hours after the first dose (T1) of the vaccine, immediately before the second dose (T2 ) and one to two months after the second dose (T3). Possibly a further sample will be collected within 2 years.

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Key information

Conditions

Dengue Vaccines Arbovirus Infections Dengue Flaviviridae Infections Flavivirus Infections Hemorrhagic Fevers, Viral Infections Mosquito-Borne Diseases RNA Virus Infections Vector Borne Diseases Virus Diseases

Age range

4 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

IRCCS Sacro Cuore Don Calabria

Negrar, VR, 37024, Italy

Location status: Recruiting

Location contact

Concetta Castilletti

CONTACT

[email protected]

Concetta Castilletti

PRINCIPAL_INVESTIGATOR

About this study

This is a non-profit, single-center, drug-based observational study whose primary objective is to characterize dengue-specific humoral and cellular immunity induced by the Qdenga® vaccine in vaccinees.

The study involves the enrollment of all pediatric subjects (age ≥ 4 years) and adults who present themselves at the DITM travel clinic for the administration of the Dengue vaccine; 402 patients are expected to be enrolled and will be asked to undergo a blood sample at the time of administration of the first dose (T0), 24-48 hours after the first dose (T1) of the vaccine, immediately before the second dose (T2 ) and one to two months after the second dose (T3). Possibly a further sample will be collected within 2 years (T4). The samples thus collected will be analyzed for the characterization of innate immunity, the characterization of cellular immunity and the characterization of the humoral response.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Subjects of both sexes presenting to the DITM to receive the anti-DENV vaccine whether or not they have had a history of prior DENV or other flaviviruses infection or a history of prior vaccination against other flaviviruses. These data will be recorded in the study CRF.
  • Age >= 4 years.
  • Signed informed consent.

Exclusion criteria

  • Age < 4 years.
  • Absence of signed informed consent.

Treatment and study plan

Qdenga

Drug

Administration of Dengue vaccine and blood sample collection

Primary outcomes

  1. Anti-DENV antibodies

    Time frame: BEFORE administration of the first dose (Time 0 = T0), immediately BEFORE the second dose (Time 2 = T2) of vaccine, and one to two months after the second dose (Time 3 = T3)

    Anti-DENV antibodies quantities (IgG and IgM, continuous variables unity of measure: Antibody titre dilution) BEFORE administration of the first dose (T0), immediately BEFORE the second dose (T2) of vaccine, and one to two months after the second dose (T3)

Secondary outcomes

  1. Innate immunity response

    Time frame: BEFORE administration of the first dose (T0), after 24-48h after the first dose (Time 1 = T1)

    Type I and II IFN and IFN-inducible genes, specific cytokines and chemokines induced by Qdenga® vaccine (continuous variables: deltaCt mRNA expression and Optical Density (OD)) at T0 and T1

  2. Cellular response

    Time frame: At the moment of the administration of the first dose (T0), immediately before the second dose (T2), and one to two months after the second dose (T3)

    • immunophenotype asset: results of the flow cytometry profiles (proportions of cells),
    • specific T- and B-cells response to viral peptides: analysis results of T- and B-cells stimulation with DENV specific peptides (continuous variables, unity of measure: Optical Density (OD)) at T0, T2 and T3.

  3. Quantitative and qualitative anti-DENV antibody response

    Time frame: At the moment of the administration of the first dose (T0), immediately before the second dose (T2), and one to two months after the second dose (T3)

    • anti-DENV antibodies quantities (IgG and IgM, continuous variables unity of measure: Antibody titre dilution) at T0, T2 and T3,
    • Analysis results of neutralization assays against different DENV serotypes (continuous variables, unity of measure: TCID50/ml) at T0, T2 and T3,

  4. Humoral response

    Time frame: At the moment of the administration of the first dose (T0), immediately before the second dose (T2), and one to two months after the second dose (T3)

    • Analysis results humoral response against different flaviviruses (IgG and IgM, continuous variables unity of measure: Antibody titre dilution) at T0, T2 and T3,
    • Analysis results of DENV specific avidity assays (unity of measure: Index);
    • Previous infections with (y/n) or vaccinations against (y/n) other flaviviruses

  5. Cell mediated response

    Time frame: At the moment of the administration of the first dose (T0), immediately before the second dose (T2), and one to two months after the second dose (T3)

    Analysis results cell mediated response against different flaviviruses (continuous variables, unity of measure: Optical Density (OD)) at T0, T2 and T3.

Study contacts

Contact information is provided by the study sponsor or research team.

Elvia Malo

CONTACT

[email protected]

+390456013111

Sponsors and collaborators

Lead sponsor

IRCCS Sacro Cuore Don Calabria di Negrar

Other

Registry information

Official study title

Characterisation of Dengue Vaccine (Qdenga®, TAK-003)-Induced Humoral and Cellular Specific Immunity in Vaccinees With and Without Prior Exposure to Flavivirus Infections or Vaccination

Acronym: VaQDENV

Important dates

Study start
2024
Primary completion
2028
Study completion
2028
First posted
Jan 15, 2025
Registry last updated
May 18, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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