A monkeypox nanovaccine candidate based on three protein antigens and silica nanoparticles

Area of Science:

• Virology
• Immunology
• Nanotechnology

Background:

• Monkeypox (Mpox) is a highly transmissible zoonotic viral disease requiring safe and effective vaccines.
• Protein-based vaccines offer high safety and specificity but often need adjuvants and delivery systems to enhance immunogenicity.

Purpose of the Study:

• To develop and evaluate a novel nanovaccine platform for mpox using specific viral antigens, a STING agonist adjuvant, and silica nanoparticles.
• To assess the immunogenicity, protective efficacy, and safety of the developed nanovaccine.

Main Methods:

• Conjugation of mpox antigens (A29L, M1R, A35R) with silica nanoparticles via the DogTag-DogCatcher system, incorporating STG-982 (STING agonist) as an adjuvant.
• Evaluation of vaccine-induced immune responses, including antibody production, cytokine profiles (Th1/Th2), T-cell activation (CD4+, CD8+), and memory cell generation in mice.
• Assessment of protective efficacy through lethal ectromelia virus challenge and evaluation of organ toxicity.

Main Results:

• The nanovaccine induced robust antigen-specific antibody responses, balanced Th1/Th2 cytokine profiles, and strong CD4+ and CD8+ T-cell responses.
• Durable memory B- and T-cell populations were stimulated, along with enhanced splenocyte proliferation.
• Triple immunization provided 100% protection against lethal ectromelia virus challenge in mice without observed organ toxicity.

Conclusions:

• The developed nanovaccine represents a safe, potent, and durable platform for mpox prevention.
• This adaptable vaccine technology holds potential for combating other emerging viral pathogens.