Intranasal influenza vaccination using an outer membrane vesicle platform

Area of Science:

• Vaccinology
• Immunology
• Biotechnology

Background:

• Traditional egg-based influenza vaccines have limitations including long production times and difficulty matching circulating strains.
• Current intramuscular vaccines primarily induce systemic immunity, with limited mucosal immune responses crucial for respiratory pathogens.
• Mucosal vaccination strategies are being explored to enhance protection against airborne infections like influenza.

Purpose of the Study:

• To develop and evaluate an intranasal influenza A vaccine candidate utilizing an outer membrane vesicle (OMV) platform.
• To assess the immunogenicity and protective efficacy of the OMV-based intranasal vaccine in a mouse model.

Main Methods:

• Outer membrane vesicles (OMVs) were engineered for high-density covalent decoration with recombinant influenza A hemagglutinin (HA) antigen.
• The OMV-HA vaccine candidate was administered intranasally to mice three times over a two-week interval.
• Immune responses (IgG, IgA) and protection against influenza virus challenge were measured post-vaccination.

Main Results:

• Intranasal vaccination with the OMV-HA candidate induced antigen-specific IgG after two doses.
• A significant induction of IgA was observed in nasal lavage fluid and lung tissue, indicating strong mucosal immunity.
• Vaccinated mice showed no detectable influenza virus in nasal or lung tissues post-challenge and were protected from clinical signs of disease.

Conclusions:

• The intranasal OMV influenza vaccine candidate successfully elicits a robust mucosal immune response.
• This OMV-based vaccine demonstrates significant protective efficacy against influenza A virus challenge.
• The OMV platform offers a promising approach for developing next-generation intranasal influenza vaccines.