Tropical Influenza Control Strategies for the Elderly (TROPICS1)

November 9, 2017 updated by: Tan Tock Seng Hospital

A Single-centre, Randomised, Observer-blind, Active Comparator-controlled, Superiority Trial of the Immune Response to Six-monthly Versus Annual Standard Dose Inactivated Trivalent Influenza Vaccination in the Elderly

TROPICS1 is a randomized, observer-blind, active comparator-controlled, single-center, Phase IV trial in 200 participants aged ≥65 years. The control group will receive a standard dose licensed trivalent inactivated influenza vaccine at day 1, and an active-comparator (Tetanus-diphtheria-pertussis vaccine) at day 180. Participants in the experimental group will receive the same influenza vaccine at day 1 and day 180. Endpoints are immunological, and include measures of haemagglutination-inhibition (HI) titres, micro-neutralisation titres and cell-mediated immunity at 4 time points after the initial vaccination up to Day 360. The primary hypothesis is that participants receiving an influenza booster at day 180 will achieve superior influenza seroprotection (HI titre ≥1:40) at day 208, compared to controls.

The World Health Organization (WHO) estimates the global annual burden from seasonal influenza as 1 billion infections, with 3-5 million severe cases and 300,000-500,000 deaths. The pattern and impact of these infections varies considerably with climate. In temperate countries, influenza epidemics characteristically occur during the cold winter months, while in sub-tropical countries, they coincide with the rainy seasons. Closer to the equator, influenza virus activity is more complex. In Singapore, biannual epidemics are usual, but with continuous transmission year-round. Bi-annual epidemics, tri-annual epidemics and year round virus activity have also been described in other tropical countries, from Indonesia and Malaysia to Peru and Mexico.

There is no published data reporting year-round influenza vaccine effectiveness in the elderly from countries with continuous influenza virus activity. Despite numerous studies worldwide exploring the HI antibody response to influenza vaccination, the majority of these do not continue follow up beyond seroconversion (21-28 days). However, of the few available, HI antibody titres declined following influenza vaccination in the elderly, such that within 6-12 months geometric mean titres approached pre-vaccination levels. With biannual epidemics and year-round transmission in tropical regions, year-round seroprotection may be important to reduce influenza infections in this environment. A six-monthly vaccination cycle would correspond with the decline in vaccine-induced seroprotection in the elderly, and the 6-monthly periodicity of outbreaks in Singapore and other tropical countries.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
200

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Singapore
      • Singapore, Singapore
        • Institute of Infectious Disease and Epidemiology, Tan Tock Seng Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

65 years and older (OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Age ≥65 years on the day of inclusion
  2. No influenza vaccination in the previous 10 months
  3. No tetanus, diphtheria or pertussis vaccine in the previous 1 year
  4. No virologically confirmed influenza infection in the previous 10 months
  5. Able to provide written informed consent
  6. Able to attend all scheduled visits and comply with all trial procedures

Exclusion Criteria:

  1. Participation in the 4 weeks preceding the first trial vaccination or participation during the present trial period in another trial investigating a vaccine, drug, medical device, or medical procedure
  2. History of a life threatening reaction to the vaccine used in the trial, or to a vaccine containing any of the same substances

  3. Known systemic hypersensitivity to any of the vaccine components, including:

    • Egg protein (eggs or egg products)
    • Chicken products
    • Formaldehyde
    • Neomycin or kanamycin
    • Octoxinol 9 (Triton X-100)
    • Cetyltrimethylammonium bromide (CTAB)
  4. History of Guillain-Barré syndrome (GBS) within 6 weeks following previous influenza vaccination
  5. Acute respiratory infection on the day of enrolment
  6. Moderate or severe acute illness/infection (according to investigator judgement) on the day of vaccination, or febrile illness (temperature ≥ 37.5°C). A prospective subject should not be included in the study until the condition has resolved or the febrile event has subsided.
  7. Self-reported thrombocytopenia, contraindicating Intramuscular vaccination
  8. Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding six months; or long-term systemic corticosteroid therapy (prednisolone ≥ 7.5mg/day or equivalent for more than 2 consecutive weeks within the past 3 months)
  9. Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion
  10. Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily
  11. Current alcohol abuse or drug addiction that might interfere with the ability to comply with trial procedures in the opinion of the Investigator

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: PREVENTION
  • Allocation: RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: SINGLE

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
EXPERIMENTAL: Six-monthly influenza vaccine
Standard dose trivalent inactivated seasonal influenza vaccine will be administered at day 1 and 180
Biological: Influenza vaccine
Administered at day 1
Biological: Influenza vaccine
Administered at day 180
ACTIVE_COMPARATOR: Annual influenza vaccine
Standard dose trivalent inactivated seasonal influenza vaccine will be administered at day 1 and an active-comparator (Tetanus-diphtheria-pertussis) at day 180
Biological: Influenza vaccine
Administered at day 1
Biological: Influenza vaccine
Administered at day 180
Biological: Tetanus-diphtheria-pertussis vaccine
Administered at day 180

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Seroprotection (Proportion of subjects with HI titre ≥1:40 (1/dil) at day 208 post-primary vaccination for each of the influenza strains present in the administered influenza vaccine)
Time Frame: Day 208 post-vaccination
Proportion of subjects with HI titre ≥1:40 (1/dil) at day 208 post-primary vaccination for each of the influenza strains present in the administered influenza vaccine.
Day 208 post-vaccination

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Geometric mean titres
Time Frame: Day 208 to 360 post-vaccination
Comparison by vaccination group of Geometric mean titres (GMTs) post-primary vaccination against homologous and heterologous influenza strains to those present in the administered influenza vaccine.
Day 208 to 360 post-vaccination
Geometric mean ratio
Time Frame: Day 208 to 360 post-vaccination
Comparison by vaccination group of the Geometric mean ratio (GMR) post-primary vaccination against homologous and heterologous influenza strains to those present in the administered influenza vaccine.
Day 208 to 360 post-vaccination
Seroprotection (Proportion of subjects with HI titre ≥1:40 (1/dil) at day 208 post-primary vaccination for each of the influenza strains present in the administered influenza vaccine)
Time Frame: Day 360 post-vaccination
Comparison by vaccination group of the proportion of subjects with HI titre ≥1:40 (1/dil) at day 360 post-primary vaccination for each of the influenza strains present in the administered influenza vaccine.
Day 360 post-vaccination
Seroconversion (Proportion of subjects achieving seroconversion after vaccination for each of the influenza strains present in the administered influenza vaccine)
Time Frame: Day 208 to 360 post-vaccination
Comparison by vaccination group of the proportion of subjects achieving seroconversion after vaccination for each of the influenza strains present in the administered influenza vaccine. Seroconversion is defined as a pre-vaccination HI titre < 1:10 and a post vaccination titre ≥1:40, or a pre-vaccination titre > 1:10 and a minimum fourfold rise in HI titre.
Day 208 to 360 post-vaccination
Micro-neutralization titres
Time Frame: Day 208 to 360 post-vaccination
Comparison by vaccination group of Micro-neutralization titres post-primary vaccination against strains present in the administered influenza vaccine.
Day 208 to 360 post-vaccination
Influenza-like illness
Time Frame: Day 208 to 360 post-vaccination
Comparison by vaccination group of the number of subjects reporting an influenza-like illness
Day 208 to 360 post-vaccination
Influenza infection
Time Frame: Day 208 to 360 post-vaccination
Comparison by vaccination group of the number of subjects with PCR confirmed influenza infection
Day 208 to 360 post-vaccination
Healthcare utilization
Time Frame: Day 180 to 360 post-vaccination
Comparison by vaccination group of the number of subjects reporting healthcare utilization. This is defined as unscheduled physician visits, emergency room visits and hospitlizations.
Day 180 to 360 post-vaccination
Solicited and unsolicited adverse events
Time Frame: Day 1 to 7 and day 180 to 187
Frequency and severity of solicited local (injection site) and systemic adverse events for 7 days post-vaccination
Day 1 to 7 and day 180 to 187
Serious adverse events
Time Frame: Day 1 to 28, and day 180 to 208
A serious adverse event is defined as any untoward medical occurrence that is an important event.
Day 1 to 28, and day 180 to 208

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Tan Tock Seng Hospital

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Healthcare Group, Singapore

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Barnaby Young, Tan Tock Seng Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ACTUAL)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 1, 2016

Primary Completion (ACTUAL)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2017

Study Completion (ACTUAL)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 1, 2017

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 12, 2016

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 13, 2016

First Posted (ESTIMATE)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 14, 2016

Study Record Updates

Last Update Posted (ACTUAL)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 14, 2017

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 9, 2017

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2015/01047

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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