Coronaviruses are the largest group of known positive-strand RNA viruses. Coronavirus infection can affect various animal species, as well as humans. Over the past two decades, coronaviruses have caused epidemic outbreaks of two respiratory diseases: the Middle East Respiratory Syndrome and Severe Acute Respiratory Syndrome. At the end of 2019, a new type of virus was detected in China. The virus has been spread by humantohuman transmission and has caused a viral pneumonia outbreak. The emergence of a new coronavirus proves that the diseases caused by this group of viruses pose a threat to global health due to the potential for a pandemic, and, therefore, need careful monitoring. The objective of the study was to analyse the current epidemic situation for the new coronavirus infection (COVID-19) caused by SARS-CoV-2, taking into account previous outbreaks of infections caused by MERS-CoV and SARS-CoV β-coronaviruses which pose the greatest threat to human health. The review briefly describes two epidemic outbreaks caused by SARS-CoV (2002–2004) and MERS-CoV (2012–present), summarises the current epidemic situation for the new SARS-CoV-2 coronavirus, describes the main restrictive measures undertaken to prevent the spread of infection in Russia. The paper considers aspects of potential specific therapy and the development of prophylactic vaccines against the new coronavirus infection. The review concludes that SARS-CoV-2 has pandemic potential and that new strains of β-coronaviruses are likely to cause outbreaks in the future. The paper points to the need for careful monitoring of the disease and conducting preventive anti-epidemic measures to curb the spread of infection.

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.

Hemophilia is an orphan disease associated with deficiency or complete lack of certain blood coagulation factors due to mutation of genes encoding their synthesis. Patients with hemophilia need continuous replacement therapy with coagulation factor products which are produced by recombinant DNA technology or derived from donated blood plasma. The development of new products or improvement of the production process of already authorised medicinal products involve clinical trials that have to include both previously treated and untreated patients of different age groups. The aim of the paper was to perform an analytical review of general hemophilia issues and major requirements for clinical trials of coagulation factor IX products based on the updated documents of the European Medicines Agency. The paper summarises the basic principles of conducting clinical trials of coagulation factor IX products that are submitted for marketing authorisation as “new” products, based on recommendations of Russian and international regulatory documents, including the updated guideline of the European Medicines Agency. It sums up product safety issues associated with undesirable immunogenicity resulting in formation of inhibitors that provoke allergic reactions or reduce the effectiveness of therapy. The harmonisation of the requirements for clinical trials during preparation and updating of documents by Russian manufacturers should be based on the analysis of the experience with hemophilia products and latest scientific achievements in the disease treatment. In that case it will facilitate the introduction of innovative efficacious hemophilia products into clinical practice.

Enzyme replacement therapy (ERT) is one of the most efficient treatments for lysosomal storage diseases. Type 1 Gaucher disease is caused by β-glucocerebrosidase enzyme deficiency, which may be compensated for by intravenous infusions of imiglucerase—a recombinant enzyme. Imiglucerase targets macrophages and enters these cells via interaction with mannose receptors on the cell membrane. Characterisation of internalization of enzymes by target cells is important in the context of the development of new medicines and production of existing ERT medicines. The peritoneal and alveolar macrophages, as well as macrophages of the spleen of small laboratory animals (rats and mice) are widely used in such studies. However, isolation of cells from animal sources raises ethical issues, and therefore continuous mammalian cell lines may offer an attractive alternative. The aim of the study: to conduct comparative studies on the internalization of recombinant imiglucerase into mouse peritoneal macrophages and L929 mouse fibroblasts. Materials and methods: CerezymeR batches 7HV0913, C6214H05, 7HV0888 (Genzyme Ltd., UK); Glurazim batches 020416, 011117, 021117 (LLC “IBC “Generium”, Russia). We used peritoneal macrophages obtained from BALB/c mice and L929 mouse fibroblasts. The cells were cultured in DMEM/F12 complete growth medium with 10% fetal bovine serum. The activity of imiglucerase internalized into the cells was evaluated spectrophotometrically by hydrolysis of the artificial substrate—4-methylumbelliferyl-β-Dglucopyranoside. Results: the study compared internalization of recombinant imiglucerase (the active ingredient of CerezymeR and Glurazim) by mouse peritoneal macrophages and L929 mouse fibroblasts. It was demonstrated that the medicines activity in the lysates of peritoneal macrophages is comparable with that in the lysates of L929 mouse fibroblasts. Regardless of the model system, the activity of Glurazim stayed within the acceptable range (80–125%) established for biosimilar products. Conclusions: the experiments proved that L929 mouse fibroblasts could be recommended for assessment of internalization of recombinant imiglucerase.

Ebola outbreak in eastern parts of the Democratic Republic of the Congo in 2018–2020 proved that the virus remains highly hazardous for humans, and the outbreak in West Africa in 2014–2016, which was the largest Ebola outbreak in history, showed that it could be imported to other continents, including Russia. In 1993 the Federal State Budgetary Institution “48th Central Scientific Research Institute” of the Russian Ministry of Defence developed a specific equine immunoglobulin for emergency prophylaxis of Ebola in risk groups. The evaluation and improvement of the product’s properties is an important area in the development of biological defence technologies.

The aim of the study was to examine the properties of the equine anti-Ebola immunoglobulin which had been stored for a long time at 2–8 °C.

Materials and methods: the authors studied batches of heterologous anti-Ebola immunoglobulin that had been stored for 17–22 years. The properties of the product were evaluated according to the requirements of the State Pharmacopoeia of the Russian Federation, 14th ed. (Ph. Rus. 14 ed.). The specific activity of the product was determined in a plaque reduction neutralisation test using Ebola virus and African green monkey kidney cells (GMK-AH-1(D)). Immunoglobulin molecular parameters were determined by size-exclusion high-performance liquid chromatography using the test methods described in the European Pharmacopoeia 9.6 and Ph. Rus. 14 ed.

Results: the storage of anti-Ebola immunoglobulin for 17–22 years at 2–8 °C resulted in a four-fold reduction of the level of virus-neutralising antibodies against Ebola, decrease in the proportion of monomers from 98 to 74–90%, increase in the proportion of dimers and polymers, and formation of immunoglobulin molecules’ fragments. Signs of toxicity for mice were observed in one of the three product batches. Conclusions: the obtained results suggest the need to perform more studies to test the quality of antiEbola immunoglobulin batches that were stored for shorter periods of time in order to assess the stability of their initial characteristics.

Influenza is a highly contagious disease that causes annual epidemics and occasional pandemics. Birds are believed to be the source of newly emerging pandemic strains, including highly pathogenic avian influenza viruses of the subtype H7. The aim of the study: to evaluate the ability of the recombinant human adenovirus, serotype 5, which expresses genes of influenza A highly conserved antigens (ion channel M2 and nucleoprotein NP), to provide protection to laboratory mice against infection with a lethal dose of avian influenza virus, subtype H7. To achieve this goal, it was necessary to adapt influenza A virus, subtype H7 for reproduction in the lungs of mice, to characterise it, and to use it for evaluation of the protective properties of the recombinant adenovirus. Materials and methods: avian influenza virus A/Chicken/NJ/294508-12/2004 (H7N2) was adapted for reproduction in the lungs of mice by repeated passages. The adapted strain was sequenced and assessed using hemagglutination test, EID50 and LD50 for laboratory mice. BALB/c mice were immunised once with Ad5-tet-M2NP adenovirus intranasally, and 21 days after the immunisation they were infected with a lethal dose (5 LD50) of influenza virus A/Chicken/NJ/294508-12/2004 (H7N2) in order to assess the protective properties of the recombinant adenovirus. The level of viral shedding from the lungs of the infected mice was evaluated by titration of the lung homogenates in MDCK cell culture on days 3 and 6 after infection. The level of specific antibodies to H7 avian influenza virus was determined by indirect enzyme immunoassay. Results: the use of Ad5-tet-M2NP adenovirus for immunisation of the mice ensured 100% survival of the animals that had disease symptoms (weight loss) after their infection with the lethal dose (5 LD50) of H7 avian influenza virus. The study demonstrated a high post-vaccination level of humoral immune response to H7 avian influenza virus. The virus titer decreased significantly by day 6 in the lungs of mice that had been immunised with Ad5-tet-M2NP compared to the control group. Conclusion: the Ad5-tetM2NP recombinant adenovirus can be used to create a candidate pandemic influenza vaccine that would protect against avian influenza viruses, subtype H7, in particular.

Specific antiviral activity is one of the key indicators characterising pharmaceutical quality and pharmacological efficacy of interferon alpha products (IFN-α). Specific activity is determined using a bioassay measuring antiviral activity in cell culture. The aim of the study was to select the most appropriate conditions for in vitro determination of IFN-α product specific activity. Materials and methods: Vero, MDBK, Hep-2, and A-549 homologous and heterologous cell cultures, as well as vesicular stomatitis Indiana virus (VSV) and murine encephalomyocarditis (EMC) virus at a dose of 100 TCD50 /0.1 mL were used for determination of specific antiviral activity. The international reference standard of recombinant interferon alpha-2b activity (Interferon alpha 2b, human, rDNA, E. coli-derived, 2nd WHO International Standard, 1999, NIBSC Code No. 95/566) and human recombinant interferon alpha 2b in the form of solution (batch No. 040214, Pharmapark LLC, Russia) were used as IFN-α samples. Results: the analysis of the obtained data helped to determine: the combinations of cell lines and the indicator virus most sensitive to IFN-α; the optimal concentration of fetal serum in the medium, and the optimal time parameters; the preferred method of reporting test results. Conclusions: the following test conditions were found to be optimal: the MDBK/VSV and Hep-2/EMC combinations proved to be the most sensitive to IFN-α; the optimal period of interferon and cell culture incubation—24 hours; the optimal concentration of fetal bovine serum in the culture medium used for diluting interferon products—2–5%. The instrumental procedure is preferred for reporting the results of interferon antiviral activity determination, because it is up-to-date, reliable, accurate and time-efficient.