The Role of Pre-existing Cross-reactive Antibodies in Determining the Efficacy of Vaccination in Humans
An Open-label Phase 2a Clinical Trial to Test the Effect of Yellow Fever Vaccination in a Background of Japanese Encephalitis Antibodies.
1 other identifier
interventional
84
1 country
1
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
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for phase_2
Started Oct 2013
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
September 3, 2013
CompletedFirst Posted
Study publicly available on registry
September 16, 2013
CompletedStudy Start
First participant enrolled
October 1, 2013
CompletedPrimary Completion
Last participant's last visit for primary outcome
June 1, 2015
CompletedStudy Completion
Last participant's last visit for all outcomes
December 1, 2015
CompletedApril 20, 2016
April 1, 2016
1.7 years
September 3, 2013
April 19, 2016
Conditions
Keywords
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
EXPERIMENTALA 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.
Control arm
EXPERIMENTALA 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.
Interventions
IXIARO, inactivated, adsorbed vaccine. Two doses (0.5 ml each) of IXIARO one month apart
Eligibility Criteria
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
- Singapore General Hospitallead
- Duke-NUS Graduate Medical Schoolcollaborator
Study Sites (1)
Singhealth Investigational Medicine Unit
Singapore, 169608, Singapore
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.
PMID: 25872531DERIVED
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Jenny Low Guek Hong
Singapore General Hospital
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