Immunogenicity and Safety of a Tetravalent Dengue Vaccine Booster Injection in Subjects Who Previously Completed a 3-dose Schedule
Condition: Dengue Fever; Dengue Hemorrhagic Fever
MeSH terms: Dengue; Hemorrhagic Fevers, Viral; Severe Dengue; Fever
Intervention: CYD Dengue Vaccine (5 dose formulation); Placebo, NaCl 0.9%
Intervention description: 0.5 mL, Subcutaneous; 0.5 mL, Subcutaneous
Phase: Phase 2
Study type: Interventional
Primary purpose: Prevention
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Masking description: An observer-blind procedure was followed for the injection of CYD dengue vaccine or placebo. Neither the blind-observer Investigator nor the participants (and/or participants' parent(s)/legally acceptable representative(s) for participants aged < 21 years) knew which product was administered.
Enrollment: 118.0
Sex: All
Minimum age: 14 Years
Maximum age: 50 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Dengue Hemorrhagic Fever; Dengue Virus; CYD Dengue Vaccine

Summary:

      The aim of the study was to assess and describe the booster effect of a tetravalent CYD
      dengue vaccine dose administered about 5 years or more after the completion of a 3-dose
      vaccination schedule in Singapore.

      Primary Objective:

        -  To demonstrate the non-inferiority in terms of geometric mean of titer ratios (GMTRs) of
           a CYD dengue vaccine booster compared to the third CYD dengue vaccine injection in
           participants from CYD28 trial (participants from Group 1 only).

      Secondary Objectives:

        -  If the primary objective of non-inferiority achieved: To demonstrate the superiority, in
           terms of GMTRs, of a CYD dengue vaccine booster compared to the third CYD dengue vaccine
           injection in participants from CYD28 trial (participants from Group 1 only).

        -  To describe the immune responses elicited by the CYD dengue vaccine booster or placebo
           injection in participants who received three doses of the CYD dengue vaccine in the
           CYD28 trial in all participants.

        -  To describe the neutralizing antibody levels of each dengue serotype Post Dose 3 (CYD28
           participants) and immediately prior to booster or placebo injection in all participants.

        -  To describe the neutralizing antibody persistence 6 months, 1 year and 2 years post
           booster or placebo injection in all study participants.

        -  To evaluate the safety of booster vaccination with CYD dengue vaccine in all
           participants.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Had been identified as a potential participant by the Sponsor, and was included in the
             list provided to the investigator (i.e., aged 9 to 45 years on the day of first
             injection of CYD dengue vaccine in CYD28, had received 3 doses of CYD dengue vaccine
             in the CYD28 trial, and had a post-dose 3 serum sample available).

          -  Participants with good health, based on medical history and physical examination.

          -  Informed consent form (ICF) had been signed and dated by participant (based on local
             regulations), and ICF had been signed and dated by the parent(s) or another legally
             acceptable representative (and by an independent witness if required by local
             regulations).

          -  Participant and parent(s)/legally acceptable representative(s) was able to attend all
             scheduled visits to comply with all trial procedures.

        Exclusion Criteria:

          -  Participant who received any other dengue vaccination that was not part of CYD28.

          -  Participant was pregnant, or lactating, or of childbearing potential (considered of
             non childbearing potential, a female must be pre-menarche or post-menopausal for at
             least 1 year, surgically sterile, or using an effective method of contraception or
             abstinence from at least 4 weeks prior to vaccination until at least 4 weeks after
             vaccination).

          -  Participation at the time of study enrollment (or in the 4 weeks preceding the trial
             vaccination) or planned participation during the present trial period in another
             clinical trial investigating a vaccine, drug, medical device, or medical procedure.

          -  Receipt of any vaccine in the 4 weeks preceding the trial vaccination or planned
             receipt of any vaccine in the 4 weeks following the trial vaccination

          -  Receipt of immune globulins, blood or blood-derived products in the past 3 months.

          -  Known or suspected congenital or acquired immunodeficiency; or receipt of
             immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy,
             within the preceding 6 months; or long-term systemic corticosteroid therapy
             (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months).

          -  Known systemic hypersensitivity to any of the vaccine components, or history of a
             life-threatening reaction to the vaccines used in the trial or to a vaccine containing
             any of the same substances.

          -  Chronic illness that, in the opinion of the Investigator, is at a stage where it might
             interfere with trial conduct or completion.

          -  Receipt of blood or blood-derived products in the past 3 months, which might interfere
             with assessment of the immune response.

          -  Deprived of freedom by an administrative or court order, or in an emergency setting,
             or hospitalized involuntarily.

          -  Current alcohol abuse or drug addiction.

          -  Moderate or severe acute illness/infection (according to investigator judgment) on the
             day of vaccination or febrile illness (temperature >= 38.0°C). A prospective
             participant should not be included in the study until the condition had resolved or
             the febrile event had subsided.

          -  Identified as an Investigator or employee of the Investigator or study center with
             direct involvement in the proposed study, or identified as an immediate family member
             (i.e., parent, spouse, natural or adopted child) of the Investigator or employee with
             direct involvement in the proposed study.