Some scientific publications contain data suggesting the “return” or “resurgence” of pertussis. Prevention and elimination of pertussis can only be achieved by extensive immunisation of susceptible populations with a highly effective vaccine. The aim of the study was to characterise available whole-cell and acellular pertussis vaccines and to assess the feasibility of improving their quality, for instance, to demonstrate the role of lipooligosaccharide (LOS)—Bordetella pertussis cell wall antigen—in the induction of adaptive immunity. The paper summarises pathogenesis of pertussis, development of post-infection and post-vaccination immunity, and potential ways of improving pertussis vaccines. Improvement of quality of available vaccines can be achieved by reducing reactogenicity of whole-cell pertussis vaccines and enhancing immunogenic activity of acellular pertussis vaccines. One way to reduce reactogenicity of a whole-cell vaccine is to reduce the number of pertussis cells in the vaccine dose, provided that this does not affect the immunogenic activity of the product. Another possible way of reducing reactogenicity is to select vaccine strains based on the LOS endotoxin content. Improvement of acellular vaccine quality involves addressing many issues, such as identification and isolation of new protective antigens. Literature review demonstrated that LOS is a key antigen, because it is involved in the body’s immune response and ensures Th1 and Th17 cell responses to pertussis, which is crucial for protection from B. pertussis bacteria. Considering the evolutionary stability of the LOS structure, this antigen (i.e. its non-toxic oligosaccharide part) can be considered as a candidate for acellular pertussis vaccine.

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.

Clostridial myonecrosis or gas gangrene (myonecrosis) and tetanus are relatively rare nowadays, but they are still considered serious conditions associated with poor prognosis and high mortality. Life-threatening infections caused by Clostridium species have been known and studied for centuries, as they differed from other infections in terms of typical clinical manifestations, challenges of therapy and prevention. The aim of the study was to analyse the global incidence of gas gangrene and tetanus and challenges of prevention and treatment of these diseases. The review of up-to-date scientific literature demonstrated that gas gangrene continues to be a problem due to its rapid progression and challenging treatment. There are two main forms of the disease—traumatic and spontaneous. Traumatic gas gangrene is usually caused by C. perfringens, C. septicum, C. novyi (oedematiens), or C. histolyticum. Its incidence increases dramatically during wars, natural disasters, and other calamities. The literature review demonstrated that over the past 40 years there has been a rise in the frequency of spontaneous gas gangrene caused by C. septicum in people with compromised immune systems, in injecting drug users, and in women during various gynecological procedures and during normal delivery. Despite the effectiveness of the tetanus immunisation programme, the infection remains widespread in countries with insufficient vaccination coverage. The risk of tetanus in developed countries is high among elderly unvaccinated or partially vaccinated people, among injecting drug users, and vaccine refusers. The paper describes some clinical cases of gas gangrene and tetanus which demonstrate problems associated with challenging diagnosis and treatment, low awareness among primary healthcare personnel about mechanisms of anaerobic infection development, and anti-vaccination movement.

According to the World Federation of Hemophilia (WFH), there are currently about 400 thousand patients with hemophilia in the world. Severe clinical manifestations of the disease associated with a genetically determined deficiency of blood clotting factor activity require continuous replacement therapy with blood clotting medicines. Long-term use of protein-based medicines often leads to the formation of specific antibodies, which causes a decrease in or loss of efficacy of the medicine or results in severe adverse reactions, including anaphylaxis. Therefore, it is important to search for new optimal approaches to hemophilia treatment, which requires the development of new blood clotting factor products, improvement of the production technology for already authorised products, as well as the use of non-factor products. The aim of the study was to present the results of the analysis of key issues related to the development and characteristics of plasma-derived and recombinant factor VIII products, new approaches to hemophilia A treatment, including the use of non-factor products. The review summarises current data on the etiology, clinical manifestations, and complications of hemophilia A treatment. It provides information on the blood clotting factor products (plasma-derived and recombinant) used as replacement therapy. It also provides information on advanced research projects for the development of new biotechnology-derived products which have good prospects of successful clinical use.

Quality control of recombinant interferon (rIFN) products with the help of modern analytical methods, including those used for identification, is becoming increasingly relevant nowadays. Identification is especially challenging in the case of Russian rIFN products that contain not only interferon (IFN) alpha-2b, but also other active ingredients and excipients that hinder the use of physical and chemical methods. Manufacturers of such products use IFN neutralization assay with mono- and/or polyclonal antibodies for identification. The aim of the study was to assess the feasibility of using different types of antibodies in the identification test based on neutralization of IFN antiviral activity in IFN alpha-2b products containing other active ingredients and excipients in addition to IFN. Materials and methods: the following materials were used in the study: MDBK cells, vesicular stomatitis virus, samples of IFN alpha-2b products with different composition and by different manufacturers, mono- and polyclonal antibodies by different manufacturers. Identification of rINFs was carried out by a biological method based on neutralization by specific antibodies of IFN ability to suppress the cytopathic effect of the indicator virus in a cell culture using a reference standard for comparison. Results: both polyclonal and monoclonal antibodies were shown to neutralize the activity of the tested IFN alpha-2b substances. Polyclonal antibodies interact with all products containing the same active ingredients, irrespective of their composition. Monoclonal antibodies interact selectively with some products. Conclusions: polyclonal antibodies can be used for identification of any product containing IFN alpha-2b. The use of monoclonal antibodies for this purpose is limited and depends on the composition of the product.

Leptospirosis is a widespread zoonosis in Russia. The human leptospirosis vaccine produced by Rostov Research Institute of Microbiology and Parasitology has been used since 1998 to minimise risks associated with deterioration of epidemiological situation. Lately, there has been an increase in the incidence of leptospirosis caused by Leptospira interrogans serovar Canicola which is not included in the human vaccine. The aim of the study was to analyse biological properties of Leptospira interrogans serovar Canicola strains to substantiate their inclusion into human leptospirosis liquid concentrated inactivated vaccine. Materials and methods: two L. interrogans serovar Canicola strains: Udalov 480 and Sobaka 2000 were used in the study. Virulent properties of the strains were evaluated by infecting Syrian hamsters, the data on specific activity of the experimental vaccine were compared to specific activity of the leptospirosis liquid concentrated inactivated vaccine used for disease prevention. The experimental vaccine was tested for Specific safety and Abnormal toxicity according to FS.3.3.1.0014.15 Leptospirosis liquid concentrated inactivated vaccine. Results: the comparison of Udalov 480 and Sobaka 2000 strains of L. interrogans serovar Canicola revealed higher virulence of Udalov 480. The tests performed for the experimental vaccine batches demonstrated that the inclusion of Udalov 480 strain did not affect the above-mentioned properties of the vaccine. Conclusions: the study demonstrated the possibility of using L. interrogans serovar Canicola strain Udalov 480 as a component of the currently produced vaccine, and confirmed the safety and efficacy of the new vaccine.