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.
Healthy adolescents and adults received 3 doses of the tetravalent dengue vaccine 5-6 years earlier in a previous CYD dengue vaccine trial (CYD28 - NCT00880893) received either a booster injection of CYD dengue vaccine or a placebo on Day 0. They were evaluated for safety and antibody persistence of the booster injection up to 2 years post-vaccination.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
118
0.5 mL, Subcutaneous
0.5 mL, Subcutaneous
Unnamed facility
Singapore, Singapore
Unnamed facility
Singapore, Singapore
Unnamed facility
Singapore, Singapore
Geometric Mean Titers (GMTs) of Antibodies Against Each Dengue Virus Serotype Following Booster Injection With CYD Dengue Vaccine in CYD63 Compared to the Third CYD Dengue Vaccine Injection Received in Study CYD28: CYD Dengue Vaccine Booster Group
GMTs of antibodies against each of the 4 dengue virus serotype (parental strains) were assessed using the plaque reduction neutralization test (PRNT).
Time frame: 28 days post-dose 3 in CYD28 and 28 days post-booster injection in CYD63
GMTs of Antibodies Against Each Dengue Virus Serotype Before and Following Booster Injection (Inj.) With Either CYD Dengue Vaccine or Placebo
GMTs of antibodies against each of the 4 dengue virus serotype (parental strains) following booster injection were assessed using PRNT.
Time frame: Pre-booster injection (Day 0) and 28 days post-booster injection
GMTRs of Antibodies Against Each Dengue Virus Serotype Before and Following Booster Injection With Either CYD Dengue Vaccine or Placebo
GMTs of antibodies against each of the 4 dengue virus serotype (parental strains) following booster injection were assessed using PRNT. GMTRs were calculated as the ratio of GMTs post-booster injection and pre-booster injection.
Time frame: Pre-booster injection (Day 0) and 28 days post-booster injection
Percentage of Participants With Seropositivity Against Each Dengue Virus Serotype Before and Following Booster Injection With Either CYD Dengue Vaccine or Placebo
Seropositivity against each dengue virus serotype were measured using dengue PRNT. Seropositive participants were defined as the participants with neutralizing antibody titers \>=10 (1/dilution).
Time frame: Pre-booster injection (Day 0) and 28 days post-booster injection
Percentage of Participants With Seroconversion Against Each Dengue Virus Serotype Following Booster Injection With Either CYD Dengue Vaccine or Placebo
Seroconversion rates for each serotypes were defined as the percentages of participants with either a pre-booster titer \< 10 (1/dilution) and a post-booster titer \>= 40 (1/dilution), or a pre-booster titer \>=10 (1/dilution) and a \>= 4-fold increase in post-booster titer as determined by PRNT.
Time frame: 28 days post-booster injection
GMTs of Antibodies Against Each Dengue Virus Serotype Following the Third CYD Dengue Vaccine Injection Received In Study CYD28 and Before Booster Injection With Either CYD Dengue Vaccine or Placebo in CYD63
GMTs of antibodies against each of the 4 dengue virus serotype (parental strains) were assessed using the PRNT.
Time frame: 28 days post-dose 3 in CYD28 and pre-booster injection (Day 0) in CYD 63
GMTRs of Antibodies Against Each Dengue Virus Serotype Following the Third CYD Dengue Vaccine Injection Received in Study CYD28 And Before Booster Injection With Either CYD Dengue Vaccine or Placebo
GMTs of antibodies against each of the 4 dengue virus serotype (parental strains) were assessed using the PRNT. GMTRs were calculated as the ratio of GMTs post-dose 3 in CYD28 and pre-booster injection in CYD63.
Time frame: 28 days post-dose 3 in CYD28 and pre-booster injection (Day 0) in CYD63
Percentage of Participants With Seropositivity Against Each Dengue Virus Serotype Following the Third CYD Dengue Vaccine Injection Received in Study CYD28, and Following Booster Injection With Either CYD Dengue Vaccine or Placebo
Seropositivity against each dengue virus serotype were measured using dengue PRNT. Seropositive participants were defined as the participants with neutralizing antibody titers \>=10 (1/dilution).
Time frame: 28 days post-dose 3 in CYD28 and 28 days post-booster injection in CYD63
GMTs of Antibodies Against Each Dengue Virus Serotype Following Booster Injection With Either CYD Dengue Vaccine or Placebo
GMTs of antibodies against each of the 4 dengue virus serotype (parental strains) following booster injection were assessed using PRNT.
Time frame: 6 months, 12 months, and 24 months post-booster injection
GMTRs of Antibodies Against Each Dengue Virus Serotype Following Booster Injection With Either CYD Dengue Vaccine or Placebo
GMTs of antibodies against each of the 4 dengue virus serotype (parental strains) following booster injection were assessed using PRNT. GMTRs were calculated as the ratio of GMTs post-booster injection and pre-booster injection.
Time frame: Pre-booster injection (Day 0) and 6 months, 12 months, 24 months post-booster injection
Percentage of Participants With Seropositivity Against Each Dengue Virus Serotype Following Booster Injection With Either CYD Dengue Vaccine or Placebo
Seropositivity against each dengue virus serotype were measured using dengue PRNT. Seropositive participants were defined as the participants with neutralizing antibody titers \>=10 (1/dilution).
Time frame: 6 months, 12 months, and 24 months post-booster injection
Number of Participants Reporting Solicited Injection Site Reactions (Pain, Erythema, Swelling) Following Booster Injection With Either CYD Dengue Vaccine or Placebo
Solicited injection site reactions: Pain, Erythema, and Swelling. Grade 3 injection site reactions: Pain: significant; prevents daily activity; Erythema and Swelling: \>100 millimeter.
Time frame: Within 7 days after booster injection
Number of Participants Reporting Solicited Systemic Reactions (Fever, Headache, Malaise, Myalgia, Asthenia) Following Booster Injection With Either CYD Dengue Vaccine or Placebo
Solicited systemic reactions: Fever, Headache, Malaise, Myalgia, and Asthenia. Grade 3 reactions: Fever: \>=39 degree Celsius; Headache, Malaise, Myalgia, and Asthenia: significant, prevents daily activity.
Time frame: Within 14 days after booster injection
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