Revolutionary Approach in the Application of Toll-Like Receptor Agonist in Nanoparticles Formulation for Peptide-Based Subunit Vaccine.
Subunit vaccines offer a safer alternative to the classical vaccine formulation that
generally contains the whole pathogens. Subunit vaccines represent only a fraction
of the immunogenic components of the pathogenic organism. Subunit vaccines can be composed of either proteins or peptides. Even in single proteins, there are hundreds of epitopes, in which
not all of them are required to induce the desired immune responses.
Some of the unnecessary epitopes may induce unwanted reactogenic or allergic responses.
This situation has necessitated the use of peptides as antigens to create a safer and more immunologically defined vaccine than proteins. Peptide vaccines represent a fragment of the protein,
containing antigenic determinant that is capable to trigger specific
T- or B-cells-mediated immune responses.
Peptide vaccines can be produced synthetically, thus underscore the simplicity of production, possess a well-defined chemical structure and are entirely free of the biological hazards that are commonly encountered with inactivated or attenuated live pathogen vaccines.
However, peptides are prone to enzymatic degradation and poorly immunogenic, thus require its formulation with a strong adjuvant to evoke a protective and long-lasting immunity. Various types of adjuvant and their recent advancement for the delivery of vaccine antigens have been extensively reviewed.
The development and selection of adjuvant is highly important, particularly in formulating peptide vaccines in order to make it a viable option for clinical use. Understanding the immune system and factors that can stimulate the presentation of the peptide antigens for further immunological processing should be of priority when developing a peptide-based vaccine.
Vaccin Res Open J. 2018; SE(1): Se1-Se3. doi: 10.17140/VROJ-SE-1-101
