Trivalent Subunit Vaccine Candidates for COVID-19 and Their Delivery Devices

Area of Science:

• Nanotechnology
• Vaccine Development
• Virology

Background:

• The COVID-19 pandemic necessitates rapid vaccine development for emerging viral threats.
• Current vaccines targeting the SARS-CoV-2 spike protein face challenges like cold-chain requirements, prime-boost schedules, and emerging variants of concern (VOCs).

Purpose of the Study:

• To develop a novel, thermally stable nanotechnology vaccine platform for SARS-CoV-2.
• To identify conserved viral epitopes for broad protection against VOCs.
• To create self-administering vaccine formulations.

Main Methods:

• Identification of three conserved neutralizing peptide epitopes from SARS-CoV-2.
• Formulation of vaccine candidates using cowpea mosaic virus (CPMV) and bacteriophage Qβ virus-like particles (VLPs).
• Development of single-dose injectable slow-release polymer implants and microneedle (MN) patches for self-administration.

Main Results:

• Vaccine candidates demonstrated high thermal stability, eliminating cold-chain dependency.
• Immunization in mice produced high antibody titers that blocked receptor binding and neutralized SARS-CoV-2.
• Formulations enabled single-dose or self-administration, overcoming logistical hurdles.

Conclusions:

• A versatile nanotechnology vaccine platform offers a stable, accessible solution for COVID-19 and future viral diseases.
• The platform allows for rapid adaptation to new viral mutants or emergent threats by exchanging epitopes.
• CPMV and Qβ VLPs can be stockpiled for rapid response to public health emergencies.