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Live attenuated influenza vaccine

The University of Hong Kong · FDA-approved active Biologic

This vaccine contains live but weakened influenza viruses that replicate in the nasal mucosa to stimulate both mucosal and systemic immune responses without causing disease.

A live attenuated influenza vaccine stimulates immune responses by introducing weakened influenza virus strains that replicate in the nasal mucosa without causing severe disease. Used for Influenza prevention in children and adults.

At a glance

Generic nameLive attenuated influenza vaccine
Also known asLAIV, Fluenz, Flumist, FluMist, FLUMIST by Mediummune.
SponsorThe University of Hong Kong
Drug classLive attenuated vaccine
ModalityBiologic
Therapeutic areaImmunology
PhaseFDA-approved

Mechanism of action

The attenuated virus strains are temperature-sensitive and replication-defective, allowing them to grow in the cooler upper respiratory tract but not in the warmer lower respiratory tract or systemic circulation. This triggers innate and adaptive immune responses including antibody production and T-cell activation against influenza antigens. The mucosal replication site provides direct stimulation of respiratory tract immunity, which is particularly relevant for preventing influenza infection at the site of viral entry.

Approved indications

Common side effects

Key clinical trials

Primary sources

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SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

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