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Completed

NCT Number: NCT04080245

Functional Consequences of T-bet Expression in Flu-specific Memory B Cells After Live Attenuated Influenza Vaccine (LAIV)

As yet the investigators do not understand if there are biomarkers of immune protection after the Flumist or Live Attenuated Flu Vaccine (LAIV). Here the investigators test the hypothesis that the T-bet expressing fraction of flu-specific B cells after live attenuated influenza vaccination also serves as an early biomarker of long-lived antibody responses after vaccination. In this study the investigators will be providing the LAIV to up to 10 healthy subjects and assaying their immune response and then providing the intramuscular influenza vaccination and testing to see if the immune protection after the LAIV also protects after the intramuscular influenza vaccination.

Update: We have amended this protocol to study the antigen-specific B cell populations that circulate after LAIV or IIV prime and LAIV or IIV boost.

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Key information

Conditions

Influenza, Human Infections Orthomyxoviridae Infections RNA Virus Infections Respiratory Tract Diseases Respiratory Tract Infections Virus Diseases

Age range

18 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

University of Alabama at Birmingham

Birmingham, Alabama, 35294, United States

About this study

Previously (1) the investigators established that a fluorochrome labeled reagent with the influenza antigen hemagglutinin accurately identified flu-specific B cells after inactivated influenza vaccination and we established that a subset of these flu-specfiic B cells that express the lineage defining master transcriptional regulator, T-bet, correlate with long lived antibody responses. As yet the investigators do not understand if there are biomarkers of immune protection after the Flumist or Live Attenuated Flu Vaccine (LAIV). Here the investigators test the hypothesis that the T-bet expressing fraction of flu-specific B cells after live attenuated influenza vaccination also serves as an early biomarker of long-lived antibody responses after vaccination. In this study the investigators will be providing the LAIV to up to 10 healthy subjects and assaying their immune response and then providing the intramuscular influenza vaccination and testing to see if the immune protection after the LAIV also protects after the intramuscular influenza vaccination.

Update: We have amended this protocol to study the antigen-specific B cell populations that circulate after LAIV or IIV prime and LAIV or IIV boost.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Missed getting the flu vaccine in the last year
  • No history of reactive airway disease
  • No history of allergy to LAIV
  • No history of allergy to IIV
  • Self-identify as healthy without an immunocompromising condition defined as cancer, autoimmune disease, organ transplant or receipt of steroids.

Exclusion criteria

  • History of reactive airway disease
  • History of allergy to LAIV or IIV
  • Do not self-identify as healthy

Treatment and study plan

Treatment Group Live Attenuated Flu Vaccine (LAIV)

Biological

We will administer LAIV once as a vaccine prime and IIV once as a vaccine boost with serial weekly blood draws for a month to validate a biomarker of LAIV efficacy.

Primary outcomes

  1. Outcome Measure: Participants with a positive T-bet expressing Flu-specific B cell subtype

    Time frame: Baseline

    The investigators will perform a blood test on lymphocytes from circulating blood.

  2. Outcome Measure: Participants with a positive T-bet expressing Flu-specific B cell subtype

    Time frame: 7 days post first injection

    The investigators will perform a blood test on lymphocytes from circulating blood.

  3. Outcome Measure: Participants with a positive T-bet expressing Flu-specific B cell subtype

    Time frame: 14 days post first injection

    The investigators will perform a blood test on lymphocytes from circulating blood.

  4. Outcome Measure: Participants with a positive T-bet expressing Flu-specific B cell subtype

    Time frame: 7 days post second injection

    The investigators will perform a blood test on lymphocytes from circulating blood.

Sponsors and collaborators

Lead sponsor

University of Alabama at Birmingham

Other

Registry information

Acronym: LAIV

Important dates

Study start
2019
Primary completion
2025
Study completion
2025
First posted
Sep 6, 2019
Registry last updated
Jun 11, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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