NCT01943305

Brief Summary

Epidemic viral diseases have become more prevalent in recent years. Among the various strategies to prevent such epidemics, vaccination is the most cost-effective. However, populations that are immunized are typically already exposed to multiple previous vaccinations or natural infections. Studies from this and other laboratories have revealed that pre-existing dengue antibodies can either inhibit or enhance subsequent dengue infection depending on the pre-existing antibody levels. While cross-reactive antibody is potentially pathogenic in dengue, how it impacts immune response to vaccination is unclear. Indeed, aggregated at the site of vaccination and the respective draining lymph nodes are antigen-presenting and immune regulatory cells that express Fc receptors and play pivotal roles in determining the magnitude and polarity of the immune response. Vaccine uptake by these antigen-presenting cells may thus be either inhibited or enhanced when vaccines are opsonized with cross-reactive antibodies. In view of the limited knowledge on how cross-reactive antibodies affect vaccination outcome, investigators propose here a study that exploits the known cross reactivity between Japanese encephalitis (JE) virus antibody and yellow fever (YF) vaccine. Investigators hypothesize that cross-reactive antibodies impacts antibody response to YF at the point vaccination in a concentration-dependent manner by altering both vaccine uptake and the innate immune response by antigen presenting cells. Investigators will structure an open label clinical trial on sequential vaccination with JE and YF vaccines, with different time intervals between vaccinations. This would test immune response to YF vaccination in subjects with different titer of cross-reactive JE vaccine-derived antibodies.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
84

participants targeted

Target at P50-P75 for phase_2

Timeline
Completed

Started Oct 2013

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

September 3, 2013

Completed
13 days until next milestone

First Posted

Study publicly available on registry

September 16, 2013

Completed
15 days until next milestone

Study Start

First participant enrolled

October 1, 2013

Completed
1.7 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 1, 2015

Completed
6 months until next milestone

Study Completion

Last participant's last visit for all outcomes

December 1, 2015

Completed
Last Updated

April 20, 2016

Status Verified

April 1, 2016

Enrollment Period

1.7 years

First QC Date

September 3, 2013

Last Update Submit

April 19, 2016

Conditions

Keywords

Yellow FevervaccinationJapanese encephalitisantibodies

Outcome Measures

Primary Outcomes (1)

  • Difference in geometric mean neutralizing antibody titer to YF17D as measured by plaque reduction neutralization test (PRNT) in volunteers receiving YF vaccination with or without prior JE vaccination

    1-month and 1-year post YF17D vaccine

Secondary Outcomes (1)

  • Innate immune response to YF vaccination at different time intervals after a prior JE vaccination

    transcriptional profiling of PBMC collected 1-day before, 1-, 3- and 7-days post YF17D vaccine

Study Arms (2)

Test arm

EXPERIMENTAL

A total of 100 healthy adults, pre-screened to be negative for anti-dengue antibodies will be enrolled upon written informed consent. 75 subjects in the test arm will received 2 doses of inactivated Japanese Encephalitis vaccine and 1 dose of Yellow Fever vaccine.

Biological: Japanese Encephalitis vaccineBiological: Yellow Fever vaccine

Control arm

EXPERIMENTAL

A total of 100 healthy adults, pre-screened to be negative for anti-dengue antibodies will be enrolled upon written informed consent. 25 subjects in the control arm will not receive Japanese Encephalitis vaccine but will receive 1 dose of Yellow Fever vaccine.

Biological: Yellow Fever vaccine

Interventions

IXIARO, inactivated, adsorbed vaccine. Two doses (0.5 ml each) of IXIARO one month apart

Also known as: Ixiaro
Test arm

STAMARIL, 1 dose (0.5 ml)

Also known as: Stamaril
Control armTest arm

Eligibility Criteria

Age21 Years - 50 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Healthy male or female adults, 21-50 years of age at the time of screening.
  • Negative for anti-dengue antibodies by ELISA.
  • Subjects who are willing to comply with the requirements of the study protocol and scheduled visits. (e.g., completion of the subject diary, return for follow-up visits) and who are willing to make themselves available for the duration of the study, with access to a consistent means of telephone contact, which may be either at home or at the workplace, land line, or mobile, but NOT a pay phone or other multiple-user device (i.e. a common-use phone serving multiple rooms or apartments).
  • Subjects who give written informed consent approved by the Ethical Review Board governing the site.
  • Satisfactory baseline medical assessment as assessed by physical examination and a stable health status. The laboratory values must be within the normal range of the assessing site or show abnormalities that are deemed not clinically significant as judged by the investigator. A stable health status is defined as the absence of a health event satisfying the definition of a serious adverse event.
  • Accessible vein the forearm for blood collection.
  • Females of non-child bearing potential due to surgical sterilization (hysterectomy or bilateral oophorectomy or tubal ligation) or menopause.
  • Female subjects of childbearing potential may be enrolled in the study
  • if they have a negative urine pregnancy test on the day of screening and negative urine dipstick pregnancy tests at the days of the vaccinations
  • if they use adequate, reliable contraception or abstain from sexual intercourse during the entire study for 1 year

You may not qualify if:

  • Presence of acute infection in the preceding 7 days or presence of a temperature ≥ 38.0°C (oral temperature assessment), or acute symptoms greater than of "mild" severity on the scheduled date of first vaccination.
  • History of severe drug and /or food allergies and/or known allergies to the trial product or its components.
  • Any condition that, in the opinion of the investigator, would complicate or compromise the study or wellbeing of the subject.
  • Woman who are pregnant or breast feeding.
  • History or presence of cardiovascular, respiratory, hepatic, renal, gastrointestinal, neuropsychiatric, or immunosuppressive disorders that would be a risk factor when administered the IP.
  • History of thymus gland disease.
  • Diagnosed with cancer or on treatment for cancer within the 3 years prior to the screening.
  • Evidence of clinically significant anaemia and other any significant active haematological disease, or having donated \> 450 mL of blood within the past three months.
  • Evidence of substance abuse, or previous substance abuse.
  • Participation in a study involving administration of an investigational compound within the past four months, or planned participation during the duration of this study.
  • Administration of any licensed vaccine, such as MMR and/or Chickenpox immunisation within 30 days before the first study vaccine dose.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Singhealth Investigational Medicine Unit

Singapore, 169608, Singapore

Location

Related Publications (1)

  • Low JG, Wijaya L, Li GK, Lim EY, Shum AK, Cheung YB, Ooi EE. The role of pre-existing cross-reactive antibodies in determining the efficacy of vaccination in humans: study protocol for a randomized controlled trial. Trials. 2015 Apr 10;16:147. doi: 10.1186/s13063-015-0651-z.

MeSH Terms

Conditions

Yellow FeverEncephalitis, Japanese

Interventions

Japanese Encephalitis VaccinesYellow Fever Vaccine

Condition Hierarchy (Ancestors)

Mosquito-Borne DiseasesVector Borne DiseasesInfectionsArbovirus InfectionsVirus DiseasesFlavivirus InfectionsFlaviviridae InfectionsRNA Virus InfectionsHemorrhagic Fevers, ViralEncephalitis, ArbovirusEncephalitis, ViralCentral Nervous System Viral DiseasesCentral Nervous System InfectionsInfectious EncephalitisEncephalitisBrain DiseasesCentral Nervous System DiseasesNervous System DiseasesNeuroinflammatory Diseases

Intervention Hierarchy (Ancestors)

Viral VaccinesVaccinesBiological ProductsComplex Mixtures

Study Officials

  • Jenny Low Guek Hong

    Singapore General Hospital

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
phase 2
Allocation
RANDOMIZED
Masking
NONE
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

September 3, 2013

First Posted

September 16, 2013

Study Start

October 1, 2013

Primary Completion

June 1, 2015

Study Completion

December 1, 2015

Last Updated

April 20, 2016

Record last verified: 2016-04

Locations