Bacterial Composition and Immune Responses in the Nose and Oropharynx During Influenza Infection

January 20, 2026 updated by: University of California, Los Angeles

This study will serve to determine how influenza infection alters the bacterial colonization patterns in the nasal and oropharyngeal compartments, and whether the immune response correlate with these alterations. The investigators will be determining bacterial composition and immune responses in the nose and oropharynx during influenza infection.

Specific Aims

Therefore, the overall aims of this study are as follows:

  1. To identify baseline composition and kinetic changes in the nasal and oropharyngeal microflora and immune responses after administering intranasal live attenuated influenza virus (i.e., FluMist® vaccine) or saline mist to healthy subjects;
  2. To identify nasal and oropharyngeal microbial composition and local immune responses during influenza infections and after resolution of infection, and correlate these changes with clinical outcomes.

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.

Detailed Description

Randomization and Post-Randomization Visits After undergoing the nasal swabs and nasopharyngeal washes, and nasal epithelial brushing, healthy volunteers will be randomly assigned to receive either saline nasal spray (placebo) or FluMist® nasal influenza vaccine (live attenuated influenza vaccine, or LAIV). They will return 1-2 weeks and 4-6 weeks later to repeat the nasal swabs and nasopharyngeal washes, and nasal epithelial brushings done at the Enrollment Visit.

Samples will be processed to isolate 16s bacterial RNA and host RNA. 16s rRNA will be analyzed by 16S sequencing for to determine the composition of the bacterial microbiome pre and post LAIV or saline (placebo) administration. Host immune responses will be assessed based upon microarray analysis of host RNA pre and post LAIV or saline administration.

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.
17

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 1

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

  • United States
    • California
      • Los Angeles, California, United States, 90095
        • UCLA

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

18 years to 64 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Healthy volunteers:
  • Healthy subjects between the ages of 18 and 65. Approximately half of the subjects will be female and approximately half will be male.
  • Must be eligible to receive live-attenuated nasal version of the influenza vaccine.
  • Must be able to provide signed and dated informed consent.
  • Healthy subjects willing and able to provide oropharyngeal and nasal cavity specimens

Exclusion Criteria:

  • Immunosuppressive conditions or medications
  • chronic systemic medical illness
  • infections or antibiotic use within the past 60 days

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

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: Live attenuated influenza vaccine
Healthy adult volunteers given intranasal FluMist (Live Attenuated Influenza vaccine). Subjects will undergo nasal swabs, nasopharyngeal washes, and nasal epithelial brushings at baseline, 1-2 weeks, and 4-6 weeks after LAIV.
Biological: LAIV
Subjects underwent nasal swabs, nasopharyngeal saline wash, and nasal brushings pre, and 1-2 weeks and 4-6 weeks following intranasal administration of LAIV.
Placebo Comparator: Saline nasal spray
Healthy adult volunteers given intranasal saline nasal spray. Subjects will undergo nasal swabs, nasopharyngeal washes, and nasal epithelial brushings at baseline, 1-2 weeks, and 4-6 weeks after saline administration.
Other: Saline
Subjects underwent nasal swabs, nasopharyngeal saline wash, and nasal brushings pre, and 1-2 weeks and 4-6 weeks following intranasal administration of saline nasal spray.
Other Names:
  • Ocean spray

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
Changes in the bacterial composition (Bacterial "microbiome") over time
Time Frame: Changes from baseline at 1-2 weeks and 4-6 weeks after LAIV or saline spray
isolation of 16S RNA from nasal swabs and nasopharyngeal washes for 16S sequencing for bacterial microbiome
Changes from baseline at 1-2 weeks and 4-6 weeks after LAIV or saline spray
Changes in gene expression in the nasal lining of study participants
Time Frame: Changes from baseline at 1-2 weeks after LAIV or saline spray
RNA isolation from nasal brushes which will undergo microarray analysis to measure changes in immune gene expression
Changes from baseline at 1-2 weeks after LAIV or saline spray

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.
University of California, Los Angeles

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.
J. Craig Venter Institute

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

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.
February 1, 2011

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.
April 1, 2014

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.
April 1, 2014

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).
November 3, 2015

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.
November 4, 2015

First Posted (Estimated)

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.
November 5, 2015

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.
January 22, 2026

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.
January 20, 2026

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.
January 1, 2026

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.
  • IRB#11-000326-CR-00003

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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