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INTRODUCTION. Respiratory syncytial virus (RSV) is one of the most widespread pathogens that typically cause acute upper and lower respiratory tract infections in children and adults. Monoclonal antibody products have long been used for passive immunoprophylaxis in premature infants with bronchopulmonary dysplasia. However, vaccines have recently been licensed for the prophylactic immunisation of older adults with various risk factors for severe RSV infection (primarily, chronic cardiovascular and respiratory diseases and diabetes mellitus).AIM. This study aimed to review the current status of the development of vaccines for active immunisation against RSV infection, including the epidemiological rationale for their development, clinical trial results for licensed vaccines, recommendations for vaccination, and promising pipeline vaccines for RSV prevention.DISCUSSION. Initially hindered by the unique immunopathogenesis of RSV infection and the genetic hypervariability of RSV for a long time, attempts to develop an RSV vaccine succeeded when international researchers managed to identify a conservative neutralising antibody target capable of inducing specific immunity against RSV. This target, the RSV capsid protein stabilised in its prefusion (pre-F) conformation, can mediate viral entry into the cell following a conformational change. Several subunit vaccines based on recombinant pre-F proteins have successfully passed clinical trials and have been approved for the immunisation of older adults. In addition, one of these vaccines has been recommended for use during pregnancy to prevent RSV infection in newborns and infants. Currently, programmes are being implemented to develop novel RSV vaccines based on messenger RNA (mRNA) and non-replicating attenuated influenza vectors. This article examines and summarises the efficacy and safety parameters of two RSV vaccines approved in multiple countries around the world. Both vaccines have satisfactory safety profiles and comparable prophylactic efficacy parameters.CONCLUSIONS. Prelicensure clinical trials of novel RSV vaccines, including those being developed in the Russian Federation, should include prophylactic efficacy assessments in target patient populations. For vaccines approved by leading international regulators, clinical trials required for approval in the Russian Federation will be limited to bridging studies confirming the immunogenicity and safety of the vaccines.

INTRODUCTION. Vaccination is the main measure for the primary prevention of human papillomavirus (HPV)-related diseases. The development of novel vaccine candidates is underway worldwide, including in the Russian Federation. At the same time, the clinical introduction of new HPV vaccines is seriously hampered by the lack of clear and unambiguous recommendations for conducting preclinical studies of these vaccines.AIM. This study aimed to analyse regulatory documents on HPV vaccines, to study the experience of conducting preclinical studies, and to summarise the preclinical approaches that could be recommended for developers and applicants seeking approval for new preventive HPV vaccines, including the vaccines being developed in the Russian Federation.DISCUSSION. The authors have analysed regulatory documents issued by the World Health Organisation (WHO), the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH), and the Council of the Eurasian Economic Commission (EEC). Additionally, the authors have reviewed the experimental results of preclinical studies of HPV vaccines. The known licensed and pipeline HPV vaccines are similar in terms of their characteristics and constructive features. However, there may be some differences in the HPV serotype coverage and the methods used to produce the HPV L1 capsid protein. To date, studies have confirmed the role of the HPV L1 capsid protein in the development of specific immunity, rendering challenge tests in animal models unnecessary. Papillomatosis modelling may be required for choosing an alternative immunological target or for studying an alternative (non-parenteral) route for vaccine administration. Preclinical study programmes may be supplemented with individual stages of comprehensive assessment of adjuvants and other additives included in novel HPV vaccine compositions.CONCLUSIONS. The authors have studied the international experience and presented a systemic overview of the methods and approaches used in preclinical studies of HPV vaccines. The authors have formulated recommendations for developers for the planning and organisation of preclinical studies of HPV vaccines (including immunogenicity, toxicity, and local tolerance assessments required for licensing new vaccines).

The safety of biological products derived from animal cells is associated with the properties of the cells themselves or their components, as well as with the possible presence of contaminants of microbial and viral origin. The suitability of cell substrate for production of prophylactic preparations is often determined by the features of the production process, which allows to benefit/risk ratio of the product. One of the common contaminants of cell substrates are mycoplasmas, type Mollicutes. As distinguished from other microorganisms they don’t have cell membranes, and parasitize a wide range of animals and plants, on the surface or inside the cells. Some mycoplasma species of are potentially pathogenic to humans, they compete for nutrients with cells in vitro , cause chromosomal aberrations, interfere with normal cell metabolism. The detection of mycoplasma contamination in cell substrates when manufacturing prophylactic preparations is required by regulatory documents.

Hepatitis A (HA) is an acute infectious disease of the liver caused by the hepatitis A virus (HAV). HA disease incidence rate is closely linked to the social and economical development. The results of seroepidemiologic studies show that the prevalence of anti-HAV antibodies in population ranges from 15 to almost 100% in various countries of the world. The only reliable way to prevent hepatitis A virus (HAV) for today is the specific prophylactic vaccination. Recently developed inactivated vaccines against HAV have been successfully used in many countries. Vaccines authorized in Russia are safe, possess low reactogenicity and high immunogenicity. Practical experience in using vaccines during the outbreaks of HAV has shown that they possess epidemiological efficacy and provide necessary protection of the population in extreme conditions. This is clearly confirmed by single administration of vaccines to patients in epidemic focus of HAV. Constant regular monitoring of the duration of protection induced by one and two doses of the vaccine is required. The article considers WHO’s position on the use of vaccines for the prevention of HA. It describes the prospects of the further use of vaccines to control the spread of HA.