Long-term Observation of Hemagglutinin and Neuraminidase Inhibition Antibody Titers After Influenza Challenge

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

ENROLLING_BY_INVITATION

Total Enrollment

200 participants

Study Classification

OBSERVATIONAL

Study Start Date

2015-07-17

Study Completion Date

2027-05-12

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

Background:

\- Influenza is a common viral infection, but it can be deadly for some people. Researchers want to learn more about how the body fights this virus. They want to study this in people who have recently been infected with influenza. They hope this can help them create more effective influenza vaccines.

Objective:

\- To learn about long-term changes in the body s immune system after influenza infection.

Eligibility:

\- People who have completed a previous LID Clinical Studies Unit influenza challenge study or current or prior participation in an LID natural history study and are willing to have samples stored for future research.

Design:

* Eligible participants will be asked to visit the clinic every 3 months for 2 years.
* During each visit, participants will have blood drawn from an arm vein using a needle and a syringe and a nasal sample.
* Participants will have a medical history and physical exam and vital signs performed. This will include blood pressure, heart rate, breathing rate, temperature, weight, and finger-measured blood oxygen. They will answer questions about any medicines taken and possible recent illnesses.
* If participants have symptoms of influenza, they may have an additional sample taken from the nose.
* Participants will complete a health questionnaire once a month on a secure website. Participants may also give their responses over the telephone....

Related Clinical Trials

Explore similar clinical trials based on study characteristics and research focus.

Characterization of the Innate Immune Response in Healthy NIH Employees at Baseline and After Immunization With the H1N1 Vaccine

NCT00995527

Healthy Volunteers

COMPLETED

Evaluation of Anti-Hemagglutinin (Anti-HA) Antibodies as Protection From the Flu in Healthy People

NCT01971255

Influenza

COMPLETED PHASE1/PHASE2

Evaluation of Influenza-Specific Immune Responses in Children and Adults During the 2010-2011 Influenza Season in the U.S.

NCT01262079

Influenza

COMPLETED

Cellular and Molecular Characterization of the Immune Response in Healthy NIH Employees atBaseline, and After Immunization With the H1N1 or Seasonal Influenza Vaccines

NCT01191853

Healthy Volunteers Influenza

COMPLETED

A Pilot Study for Collection of Anti-Influenza A Immune Plasma

NCT00984451

Influenza A Virus Infection Swine Flu

COMPLETED

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Circulating anti-influenza antibodies are an important factor in predicting clinical illness and severity in those infected with influenza. Specific antibodies against influenza include proteins targeting hemagglutinin (HA) and neuraminidase (NA). Lifelong immunity does not occur with influenza, either from natural infection or from vaccination. Due to the antigenic variation of Influenza A, individuals may become infected multiple times with the same subtype of influenza and even with the same strain. In the setting of natural infection and vaccination, antibody titer levels can persist initially, but then wane over time.

In our previous challenge studies, measurements of antibody responses have been focused solely on the acute infection period up to 2 months after initial infection. Long-term changes in immunity have not been investigated. The challenge setting gives us the unique ability to follow individuals from a specific, known and well-characterized exposure/illness to measure long-term changes in antibody titers from a pre-exposure baseline. This study could offer unique insight into how anti-influenza antibody titers change over time naturally and in response to other infections and life events. This type of controlled study has never been done and we believe monitoring titers long-term will help us better understand protective correlates of influenza.

In this natural history study, we will follow individuals who have undergone influenza challenge or have been naturally infected with influenza to evaluate changes in anti-influenza antibody titers over a 2-year period. Subjects will be followed for symptoms of influenza-like illness (ILI) and other changes in clinical status through quarterly clinical evaluations with blood draws. Monthly questionnaires will be used to follow subjects in between visits.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Post Influenza

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Observational Model Type

COHORT

Study Time Perspective

PROSPECTIVE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

1

Post influenza infection

No interventions assigned to this group

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

1. Completion of participation in an LID Clinical Studies Unit influenza challenge study or current or prior participation in an LID natural history study.
2. Willing to have samples stored for future research.

CO-ENROLLMENT GUIDELINES:

Participants may be co-enrolled in other research studies. This will be addressed on a case-by-case basis with the approval of the principal investigator (PI) or associate investigator.

If a participant enrolls in another influenza challenge study, the participant will be removed from this study. The participant can re-enroll in this study after completion of the influenza challenge study and will be followed for two years following completion of the most recent influenza challenge study.

Exclusion Criteria

Any condition or event that, in the PI s opinion, may substantially increase the risk associated with study participation or compromise the study s scientific objectives. Conditions that exclude a subject are considered to be unlikely, but an example would include a newly diagnosed medical condition that may alter a participant s immune system and make it unsafe to obtain scheduled blood samples for research purposes.

Minimum Eligible Age

18 Years

Maximum Eligible Age

120 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes