The integration of nanotechnology into immunology has paved the way for a new generation of vaccines known as nanovaccines. Due to their unique properties such as nanoscale size, high surface area, tunable surface chemistry, and ability to bypass physiological barriers nanoparticles enable effective antigen delivery, simultaneous activation of innate and adaptive immunity, and controlled release mechanisms. This article explores the role of nanoparticles in vaccine development and analyzes commonly used nanoparticle types including lipid-based, polymeric, metallic, inorganic, magnetic nanoparticles, nanogels, dendrimers, and virus-like particles in terms of their structure, function, and advantages. Nanovaccines offer notable benefits such as enhanced antigen stability, reduced dosage requirements, non-invasive administration, and improved immunogenic efficacy. However, challenges such as nanoparticle toxicity, limited stability, protein corona formation, and the difficulty of translating animal data to human applications complicate their development. COVID-19 vaccines exemplify the successful global deployment of nanotechnology in immunization. The future of nanovaccines is headed toward multifunctional, personalized mRNA platforms that support non-invasive administration routes.