One of priority issues of the present-day healthcare system is development of new vaccines and improvement of existing ones due to decreasing immunocompetence of the population, emergence of new infections and reemergence of old ones which were previously thought to be under control. Adjuvants have proven to be integral and important components of modern vaccines, as they enhance immune response to the vaccine antigen. However, despite a lot of effort put into their development, only a small number of adjuvants are currently used in clinical practice.The aim of the study was to systematise literature data on the adjuvants’ mechanisms of action, their specific structure, composition, and stimulation effects that mediate their immunoadjuvant properties. The paper summarises data on adjuvants used as components in licensed vaccines, describes their characteristics, analyses molecular mechanisms of their action in order to establish correlation between their structure and activity, which is important for the development of more efficacious and safe adjuvants. The paper cites advanced developments aimed at enhancing stimulation effects of existing adjuvants. It concludes by stating that the key research area aimed at improving vaccination efficacy is the study of mechanisms that contribute to the development of effective protection against infectious agents, as well as analysis of how to use adjuvants to stimulate the body’s defensive mechanisms, primarily by impacting the innate immunity.

The review is devoted to specific aspects of the development of post-vaccination immunity following immunisation with different types of antiviral vaccines, as well as to ways of increasing immunogenicity of vaccines and effectiveness of preventive vaccination. Vaccines containing highly purified and recombinant antigens obtained using modern technologies have lower reactogenicity and a higher safety profile, but are less immunogenic compared to live vaccines. Effective vaccines have not been developed for many viral infections yet. Therefore, it is critical to search for ways to enhance immunogenic properties of vaccines in order to increase the efficiency of vaccination, and to develop new vaccine formulations that provide reliable protection of the body against infection. The aim of the paper was to analyse specific aspects of immune response development following immunisation with antiviral vaccines, and approaches to increasing their immunogenicity using adjuvants. It reviews different types of antiviral vaccines, as well as specific aspects of immune response development depending on the nature of a specific antigen. The paper substantiates the use of adjuvants to enhance and regulate the induced immune response. It analyses mechanisms that determine the stimulating effect of adjuvants and summarises data on the adjuvants used in the licensed vaccines for human use. The authors highlight the need for further research to increase the efficiency of vaccination and suggest that one of potential solutions is the use of adjuvants based on recombinant human cytokines.

Анализ механизмов развития иммунного ответа при инфицировании вирусом гепатита В и способы повышения эффективности вакцинацииФедеральное государственное бюджетное учреждение «Научный центр экспертизы средств медицинского применения» Министерства здравоохранения Российской Федерации, Российская Федерация, 127051, г. Москва, Российская Федерация Резюме В настоящее время в медицинской практике применяется ряд рекомбинантных вакцин против гепатита В с доказанным профилем иммуногенности и безопасности. Проведение вакцинации против указанной инфекции в рамках национальных программ иммунизации в разных странах мира, в том числе в России, способствовало снижению заболеваемости гепатитом В. Однако, несмотря на наличие эффективных препаратов, существуют группы лиц, слабо отвечающих на проводимую вакцинацию. Поскольку выраженность иммунного ответа на вирус гепатита В определяется многими факторами, продолжается активный поиск подходов к повышению эффективности иммунопрофилактики при данной инфекции. В статье рассмотрены основные пути развития иммунных реакций при инфицировании вирусом гепатита В, приведены сведения о способах повышения эффективности вакцинации против указанного возбудителя инфекции, одним из которых является применение адъювантов. Представлена краткая характеристика зарегистрированных вакцин против гепатита В, содержащих разные адъюванты; рассмотрены основные механизмы их действия; обобщены результаты ряда доклинических и клинических исследований современных вакцин против гепатита В с использованием новых адъювантов, которые могут быть перспективными с точки зрения повышения иммуногенности вакцин. Понимание особенностей формирования иммунитета против вируса гепатита В в сочетании с изучением механизмов действия новых адъювантов будет способствовать созданию современных препаратов, обеспечивающих сбалансированное стимулирование гуморального и клеточного иммунного ответа против вируса гепатита В.

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.