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

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: Completed
• Conditions: Influenza
• Intervention / Treatment: Biological: LAIV; Other: Saline

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: Interventional
• Enrollment (Actual): 17
• Phase: Phase 1

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Changes in the bacterial composition (Bacterial "microbiome") over time	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	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

• Sponsor: University of California, Los Angeles
• Collaborators: J. Craig Venter Institute

Publications and helpful links

General Publications

• Tarabichi Y, Li K, Hu S, Nguyen C, Wang X, Elashoff D, Saira K, Frank B, Bihan M, Ghedin E, Methe BA, Deng JC. The administration of intranasal live attenuated influenza vaccine induces changes in the nasal microbiota and nasal epithelium gene expression profiles. Microbiome. 2015 Dec 15;3:74. doi: 10.1186/s40168-015-0133-2.

Study record dates

Study Major Dates

• Study Start: February 1, 2011
• Primary Completion (Actual): April 1, 2014
• Study Completion (Actual): April 1, 2014

Study Registration Dates

• First Submitted: November 3, 2015
• First Submitted That Met QC Criteria: November 4, 2015
• First Posted (Estimated): November 5, 2015

Study Record Updates

• Last Update Posted (Actual): January 22, 2026
• Last Update Submitted That Met QC Criteria: January 20, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Microbiota; immunology
• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Orthomyxoviridae Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Influenza, Human; Inorganic Chemicals; Chlorine Compounds; Sodium Compounds; Chlorides; Hydrochloric Acid; Sodium Chloride
• Other Study ID Numbers: IRB#11-000326-CR-00003