Hyaluronan as an immunological adjuvant:a novel application for an ancient molecule

Vaccines are among the most important scientific breakthroughs in human history.However,both the recent COVID-19 pandemic and cancer prevalence highlighted the requirements for new vaccination platforms that are more effective in stimulating complex immune responses,including the activation of CD4^(+)and CD8+T-cell-mediated immunity and the induction of immunological memory.In this regard,protein-/peptide-based vaccines represent valuable options that are based on a balance between a good safety profile and a relatively rapid manufacturing time;nonetheless,efficient adjuvants are needed for protein-based vaccines to overcome weak immunogenicity.Toll-like receptor(TLR)agonists have been advanced as promising adjuvants for the development of protein-based vaccines that can overcome all the shortcomings of clinically available formulations,as these agonists fine-tune the crosstalk between innate and adaptive immune systems.However,a critical challenge remains the identification of TLR-agonist adjuvants with increased potency but minimal toxicity.In this context,natural polymers(NPs)and their derivatives originating from plants,animals,or microbes are good candidates for use in the creation of vaccines with both high safety and efficacy profiles[1].