General characteristics of adjuvants and their mechanisms of action (part 2)

Abstract

One of the major public health challenges today is development of new vaccines and technologies to optimize the vaccination process. There is a growing scientific interest in vaccine adjuvants that enhance vaccine immunogenicity. At present, numerous studies are underway to develop COVID-19 vaccines, including inactivated and subunit vaccines which contain adjuvants for efficient induction of immune response and solid immunity. The aim of the study was to systematise literature related to the analysis of the structure, mechanisms of action and stimulating properties of vaccine adjuvants (synthetic oligodeoxynucleotides, virosomes, polyoxidonium, sovidone), as well as to summarise data on the effects of adjuvants used in SARS-CoV, MERS-CoV, and SARS-CoV-2 vaccine development studies. The paper analyses the prospects for enhancing the stimulating effect of the adjuvants when used in combination with compounds having a different mechanism of action. It also analyses the results of studies of adjuvanted vaccines against SARS-CoV and MERS-CoV, which may be useful when selecting adjuvants with optimal efficacy and safety profiles to be used in SARS-CoV-2 vaccines under development. It was concluded that understanding of the mechanisms of action of adjuvants that mediate their stimulating effect on the body’s immune system will contribute to safe and effective use of adjuvants to enhance the immunogenicity of both authorised and new vaccines.