Hemorrhagic fever with renal syndrome (HFRS) and tick-borne encephalitis (TBE) are the most common viral diseases in Russia. HFRS is caused by six different types of hantaviruses: Hantaan, Amur, Seoul, Puumala, Kurkino, and Sochi, which are transmitted to humans through small mammals of the Muridae and Cricetidae families. TBE is caused by viruses belonging to five different phylogenetic subtypes. The similarities in the ecology of HFRS and TBE pathogens is presented here. Hantavirus-infected small mammals can transmit the virus to uninfected animals, and ticks can also transmit hantavirus to other ticks and mammals. Hantavirus transmission from ticks to humans is possible only hypothetically based on indirect data. Over the past 23 years, 164,582 cases of HFRS (4.9 per 105 people) and 71,579 cases of TBE (2.5 per 105 people) were registered in Russia. The mortality rate was 0.4% (668 cases) in HFRS and 1.6% deaths (1136 cases) in TBE. There were 4030 HFRS (2.5%) and 9414 TBE (13%) cases in children under 14 years old. HFRS and TBE cases were registered in 42 out of 85 Russian regions; in 18—only HFRS, in 13—only TBE, and 12 had no reported cases. The prospects of applying a combined vaccine for HFRS and TBE prevention are shown in this paper.

Evolutionary potential of viruses can result in outbreaks of well-known viruses and emergence of novel ones. Pharmacological methods of intervening the reproduction of various less popular, but not less important viruses are not available, as well as the spectrum of antiviral activity for most known compounds. In the framework of chemical biology paradigm, characterization of antiviral activity spectrum of new compounds allows to extend the antiviral chemical space and provides new important structure-activity relationships for data-driven drug discovery. Here we present a primary assessment of antiviral activity of spiro-annulated derivatives of seven-membered heterocycles, oxepane and azepane, in phenotypic assays against viruses with different genomes, virion structures, and genome realization schemes: orthoflavivirus (tick-borne encephalitis virus, TBEV), enteroviruses (poliovirus, enterovirus A71, echovirus 30), adenovirus (human adenovirus C5), hantavirus (Puumala virus). Hit compounds inhibited reproduction of adenovirus C5, the only DNA virus in the studied set, in the yield reduction assay, and did not inhibit reproduction of RNA viruses.

Relevance. Hemorrhagic fever with renal syndrome (HFRS) and tick-borne encephalitis (TBE) are the most common natural focal diseases of viral etiology in Russia. The medical and social significance of these two infections is determined by the extensive foci of their spread, high annual morbidity rates, and the presence of severe forms of the disease can lead to permanent disability and even death. Aim. To assess the current epidemiological situation of HFRS and TBE in the Russian Federation. Conclusions. Over 23 years (from 2000 to 2022), 164,582 cases of HFRS were identified in Russia with an average annual rate of 4.9 cases per 100 thousand population, as well as 71,579 cases of TBE with an average annual rate of 2.5 cases per 100 thousand population; 668 (0.4%) and 1136 (1.6%) deaths from HFRS and TBE, respectively; 4030 (2.5%) and 9414 (13%) children under the age of 14 years among patients with HFRS and TBE, respectively. The incidence of HFRS and TBE per 100 thousand population of Russia was higher among rural residents than among urban residents. Most cases of HFRS were registered in the autumn-winter period, and TBE – at the end of June – the first half of July. Of the 85 administrative regions of Russia, cases of HFRS and TBE are registered in 42, in 18 – only HFRS, in 13 – only TBE, and in 12 regions no clinically diagnosed cases of HFRS and TBE have been identified.

Introduction. Vaccination could be the most effective means of preventing hemorrhagic fever with renal syndrome (HFRS), which is one of the leading zoonoses and a major cause of natural disease in humans. Therefore, research to develop an effective vaccine and the search for new non-toxic and effective adjuvants that can enhance and prolong the immune response, reduce the antigen concentration and reduce the frequency of dose administration is an urgent task. The aim of the study was to determine the dependence of the immunogenic activity of an experimental hantavirus vaccine based on Puumala virus (HV) on the antigen dose both in native form and in combination with carbohydrate adjuvants. Materials and methods. The immunoadjuvant effect of Ac3-LPS S. sonnei and S. flexneri 1B and emulsions of nanoemulsified squalene Sepivac SWE (SWE) as part of HV at the optimal and minimal doses was investigated by induction of neutralising antibodies after 3-fold immunisation (day 0, 14, 182) of guinea pigs (Cavia porcellus). Differences in the immunogenic activity of HV were assessed in the neutralisation reaction by 50% suppression of focal units in Vero E6 cell cultures. Results. A statistically significant increase in neutralising antibodies levels was observed after immunization both with HV at the optimal dose and for its combination with adjuvants. Ac3-LPS S. sonnei and SWE showed the most pronounced immunoadjuvant effect at concentrations of 50 and 100 μg/dose, respectively. The immunoadjuvant effect of the combination of the hantavirus vaccine with Ac3-LPS S. sonnei and SWE contributed to both an enhanced immune response and its duration. The tenfold reduction of the antigen dose in the presence of SWE allows optimization of the immune response to the vaccine. Conclusion. The results of this study show the prospects of using Ac3-LPS S. sonnei and Sepivac SWE in the vaccine for the prevention of HFRS.

Relevance. Hemorrhagic fever with renal syndrome (HFRS) is leading among natural focal human diseases in Russia, the causative agents of which - orthohantaviruses - belong to the order Bunyavirales, family Hantaviridae. More than 98% of HFRS cases in Russia are caused by the Puumala virus. It is a serious zoonosis for which there is still no specific treatment. The WHO has not approved a vaccine. The aim of this study was to investigate the effect of formaldehyde, β-propiolactone, hydrogen peroxide, ultraviolet rays, gamma irradiation and thermal inactivation on the immunogenic activity of inactivated vaccine preparations against HFRS Materials and methods. To achieve this aim, experimental vaccine preparations based on the PUU-TKD/VERO strain of Puumala virus were prepared and inactivated using the methods described above. The time intervals required for complete inactivation of the virus were determined, and the effects of the inactivators on viral RNA and immunogenic activity of the vaccine preparations were evaluated in BALB/c mouse and Syrian hamster models. Results. According to our results, vaccine preparations inactivated by different chemical and physical methods, which differ significantly in the mechanism of the mechanism of interaction with the virus, show no significant differences in immunogenic activity, except for thermal inactivation. Conclusion. A certain advantage of β-propiolactone is the short virus inactivation time, its complete degradation into non-toxic compounds within a few hours, and the reduction of total protein content after sterilization filtration, which is probably due to less aggregation of virus particles and cellular proteins

Relevance. Hemorrhagic fever with renal syndrome (HFRS) and tick-borne encephalitis (TBE) are the most common natural focal diseases of viral etiology In Russia. The medical and social significance of these two infections is determined by the extensive fociof their spread, high annual morbidity rates in the population, and the possibility of developing severe forms of the disease leading to permanent disability and death. The causative agents of HFRS In Russia are 6 types of hantaviruses Hantaan, Amur, Seoul, Puumala, Kurkino and Sochi, which, immunologically and genetically significantly different from each other, support their existence in nature through six different species of small mammals, which are sources of infection in humans. TBE virus strains that cause disease in humans belong to five phylogenetically distinct subtypes, including: Far Eastern, European, Siberian, “178-79” and Baikal. Aim. Analysis of the role of small mammals and ticks in the ecology of HFRS and TBE pathogens. Conclusions. Small mammals retain and transmit hantaviruses to uninfected animals and ticks. At the same time, ticks retain and transmit to ticks and mammals not only the TBE virus, but also hantaviruses. Despite the taxonomic difference between the viruses that cause HFRS and TBE, some of their ecological properties are similar.

During 2000–2022, a total of 69 of Russia’s 85 administrative regions reported 164,580 hemorrhagic fever with renal syndrome (HFRS) cases, with an annual average rate of 4.9 cases/100,000 population (105 popul.). European Russia reported 162,045 (98.5%) cases in 53/60 regions with 9.7 cases/105 popul. Asian Russia reported 2535 (1.5%) cases in 16/25 regions with 0.6 cases/105 popul. In the same period, Russia reported 668 (0.4%) fatal HFRS cases, and 4030 (2.4%) cases among children under the age of 14 years. Most HFRS cases occurred during autumn and winter. The incidence among rural residents was 6.7 per 105 popul., higher than the urban 4.4 per 105 popul.; however, among HFRS patients, rural and urban residents account for 35% and 65%, respectively. Six hantaviruses, causing HFRS of different clinical severity, were recognized as pathogens: Hantaan (HTNV) and Amur (AMUV) of Orthohantavirus hantanense species, Seoul (SEOV) of Orthohantavirus seoulense species, Puumala (PUUV) of Orthohantavirus puumalaense species, and Kurkino (KURV) and Sochi (SOCV) of Orthohantavirus dobravaense species, with the principal hosts Apodemus agrarius coreae, Apodemus peninsulae, Rattus norvegicus, Myodes glareolus, Apodemus agrarius agrarius, and Sylvaemus ponticus, respectively. It was found that 97.7% of HFRS cases are caused by PUUV, therefore, this virus plays the main role in the HFRS morbidity structure in Russia.

We report the effects of storage conditions and human serum albumin addition to the vaccine composition on the immunogenic properties of an experimental vaccine against hemorrhagic fever with renal syndrome. To obtain an experimental vaccine, the Puumala virus, propagated in Vero cells culture, was concentrated, inactivated with beta-propiolactone, and purified by chromatography on the CaptoCore 700 multimodal sorbent (GE Healthcare). The target component in the vaccine was 20.2 106 of viral RNA copies/ml. The humoral immune response to the vaccine was determined by measuring the neutralizing antibodies in the blood serum of immunized Syrian hamsters (Mesocricetus auratus). It was revealed that the Puumala virus inactivated with beta-propiolactone induces a pronounced humoral immune response, which indicates preservation of relevant immunogenic epitopes. Аccording to our study, viral RNA is more stable during storage of the inactivated vs. intact virus. It was confirmed that full virus inactivation occurred after 24 hours of storage at 37C. A significant decrease in the virus immunogenicity during the thermal inactivation was noted, which confirms the need for careful selection of storage conditions for thermolabile Hantaviruses. A direct correlation was observed between viral titer and viral RNA copy number/ml. Adding human serum albumin stabilized viral infectivity during storage: Puumala virus titer remained at the same level for 3 months of storage at 62C, whereas without albumin, the titer decreased to undetectable level. The addition of 0.1% human serum albumin to the inactivated virus stabilized its immunogenic properties during long-term storage. It was shown that vaccine preparations with human serum albumin (0.11%) show higher dose-dependent stability upon repeated freezing assessed by detecting viral RNA level and their immunogenicity. It can be assumed that human serum albumin provides better preservation of of viral genetic material during storage, as well the protein epitopes responsible for the protective immune response in the form of neutralizing antibodies induction, undergo less pronounced conformational changes in the presence of albumin. These data support the addition of human serum albumin to the vaccine formulation.

We worked out a method of hantavirus Puumala cultivation in Vero cells on a micro-carrier in small volumes of pseudosuspension. The results obtained demonstrate the effectiveness of this cultivation method in terms of the amount of viral harvest and the effort expended and will serve as a starting point for further scale-up of the vaccine against hemorrhagic fever with renal syndrome in the bioreactor.

In the Russian Federation, the vaccine against hemorrhagic fever with renal syndrome is at the stage of preclinical and clinical trials. The aim of the study was to analyze an effect of vaccine schedule on neutralizing antibodies (nAB) dynamics in guinea pig models applied with experimental Puumala virus based hantavirus vaccine (HV). Quantitative evaluation of neutralizing antibodies was presented as antibody titer geometric mean expressed in binary logarithms (log2) by the 50% reduction of focus-forming units (FRNT50) in Vero cell in the focus reduction neutralization test. The HV dual inoculation to guinea pigs was carried out in 14 day intervals, booster injection was applied on day 182 after the onset, in the thigh muscle tissue by using 0.3 ml undiluted (HV-u/d) and in the 1/10 dilution (HV-1/10). nAB titer on day 14 after the first HV-u/d and HV-1/10 injection was measured to be at titer of 5.50.3 and 4.80.3, respectively. After the second injection, the nAB peak was as high as 90.2 on day 42 after the first HV-u/f injection, and 6.50.2 on day 14 after the HV-1/10 injection. nAB decreased down to 6.20.3 and 50.3, respectively, on day 364 after the first injection. The booster HV-u/d and HV-1/10 injection induced increase in nAB up to 9.50.3 and 6.50.3, respectively. After the booster injection, it induced significantly higher nAB observed on day 238 after the first HV-u/d injection and delayed up to the 294 day for the HV-1/10. The results of the study indicated the early formation of the immune response, long-term nAB persistence and significantly enhanced immune response after the booster injection on day 182, which indicated a potential for the booster injection a year later. The immunological efficacy and protective activity of the vaccine schedule may be finally assessed according to the results of clinical trials.

Haemorrhagic fever with renal syndrome (HFRS) is the most widespread natural-focal human disease in the Russian Federation. In this study, we report virological assessment of a fatal case of HFRS-PUUV (Puumala virus) in the Kursk Region. The infection caused severe multiorgan failure and the maximum viral load was detected in the tissue of the spleen.Viral sequences were obtained from the patient's autopsy material and lung tissues of bank voles captured in the region. These sequences formed a new clade in the PUUV phylogenetic tree, an outgroup to all known Russian (RUS) lineage sequences. On the other hand viruses collected in the Kursk Region grouped with the RUS lineage and are separated from all other PUUV linages. We propose to nominate this novel group as W-RUS as the identified viruses were collected near the western Russian boundary. The recombination signals between their ancestors and RUS lineage representatives from the Volga region were revealed. The strain Samara_94/CG/2005 suggestively emerged as the result of reassortment between the ancestors of W-RUS and DTK-Ufa-97.

Relevance. Hemorrhagic fever with renal syndrome (HFRS) is an acute viral zoonosis. Being widespread in Eurasia, it holds a leading place in Russia among natural focal human diseases. The vast majority of HFRS cases in Russia, about 98%, are associated with Puumala virus. The disease is characterized by a wide range of clinical manifestations. Early specific diagnostics appears to be of a great importance for starting timely pathogenic therapy. The aim of the study was to clarify the diagnostic value of detecting hantavirus antibodies in the HFRS suspected patient urine. Materials and methods. Blood sera and urine samples from 68 patients at the Infectious Diseases Hospital in the city of Ufa, obtained with a 2-day interval, as well as urine and blood serum samples from 15 convalescents 1, 2, 3 and 6 months after disease onset were examined for hantavirus antibodies. 53 blood sera and urine samples from patients residing in Moscow, Moscow and Samara regions collected at different time points during the disease course were investigated in parallel. Antibodies were detected by the indirect immunofluorescence method. Results. On day 3, 4, 5 and 6 of disease, while specific antibodies were detected in the blood serum, antibodies in the urine were found in 85.7%, 89.4%, 93.1% and 100% of patients, respectively. The peak quantity of antibodies was excreted in the urine from days 5 to 11, which corresponds to the oliguric stage of the disease. In the convalescent period, antibodies were still detected in urine 1, 2 and 3 months afterwards in 86.7%, 46% and 20% of cases, respectively, but not detected 6 months later, which probably reflects the process of long-term restoration of the kidneys function. A moderate positive correlation between specific antibodies in serum and urine was observed only in the oliguric period of the disease. Conclusions. Detection of hantavirus antibodies simultaneously in blood serum and urine of febrile patients instead of paired blood sera allows to conduct HFRS diagnostics within the very first days of hospitalization and prevent severe complications due to timely pathogenic therapy.

Hemorrhagic fever with renal syndrome (HFRS) is the most common natural focal disease in the Russian Federation with about 6–12 thousand cases annually. 97.7% of all HFRS cases in Russia are caused by the Puumala virus, 1.5%—by the Hantaan, Amur, Seoul viruses, and about 0.8% by the Kurkino and Sochi viruses. There are no licensed vaccines for the prevention of HFRS in the European Region; there are no specific therapeutic to treat orthohantavirus infections. Here we report the results of candidate polyvalent HFRS vaccine preclinical studies. The vaccine was produced on the basis of three viruses: Puumala, strain PUU-TKD/VERO, Hantaan, strain HTN-P88/VERO, and Sochi, strain DOB-SOCHI/VERO. These viruses were inactivated with β-propiolacton, purified by gel filtration and aluminum hydroxide adsorbed. 18–20 g female BALB/c mice were immunized intramuscularly 2 or 3 times with a 2-week intervals and blood was taken 2 weeks after immunization. FRNT50 performed for virus specific antibodies determination. ELISA kits (Bender MedSystems, Cusabio) were used for detection of cytokines IL-1β, IL-12, INF-ɣ. Neutralizing antibodies geometric mean titers to the Puumala, Hantaan, and Sochi viruses were: 9.22 ± 0.31, 9.17 ± 0.26, 8.96 ± 0.34 log2/ml. Up to 1/32 vaccine dilution neutralizing antibodies were identified in 10/10 immunized mice with titers ≥ 3,32 log2/ml. IL-12 and INF-ɣ increased after immunization in average 5.5 and 2.8 times respectively, that reflects the Th1 type immunity stimulation. IL-1β slightly increased, that may suggest vaccine low reactogenicity. According to our preclinical investigations, the candidate polyvalent HFRS vaccine elicits balanced immune response to the Puumala, Hantaan and Sochi viruses.

Hemorrhagic fever with renal syndrome (HFRS) is an acute zoonotic disease caused by orthohantavirases Puumala, Dobrava-Belgrad (4 genotypes), Hantaan (genotype Amur) and Seoul.. In the Russian Federation, HFRS takes a leading place among all natural focal human diseases. Formalin, β-propiolactone, and ultraviolet radiation were tested to select the optimal method of virus inactivation during the development of the whole-virion vaccine against HFRS. The specific activity and the immunogenicity of the vaccine were determined, respectively, by the number of copies of viral RNA/mL and by the titer of neutralizing antibodies in the BALB/c mice blood serum in response to immunization. An analysis of the immunogenicity of vaccines inactivated with formalin, β-propiolactone or UV radiation did not reveal significant differences in the level of neutralizing antibodies they induced. At the same time, β-propiolactone has obvious technological advantages compared to formalin and UV radiation: the time of inactivation of hantavirus is reduced tenfold, neutralization of the inactivator and control of its content in the final vaccine are not required, and the amount of total protein in the vaccine decreases. hemorrhagic fever with renal syndrome, hantavirases, inactivated vaccines, neutralizing antibodies, formalin, β-propiolactone, ultraviolet

Various adjuvant effects on the immunogenicity of the candidate inactivated Puumala virus vaccine were detected in BALB/c mice. Adjuvants under study were: aluminum hydroxide, spherical particles of Tobacco mosaic virus coat protein, B subunit of heat-labile enterotoxin of Escherichia coli, and low endotoxic lipopolysaccharide of Shigella sonnei. Aluminum hydroxide (1 mg/ml) did not affect neutralizing antibodies’ induction and vaccine stability during storage compared to immunization with the vaccine without adjuvant. B subunit of heat-labile enterotoxin (0.2 µg/ml), low endotoxic lipopolysaccharide (50 µg/ml), and plant virus-based spherical particles (300 µg/ml) significantly enhance the humoral immune response of vaccine (p < 0.0001). Pronounced stimulation of IL-12 and IFN-ɣ was observed when mice were immunized with vaccines both with adjuvants (except of aluminum hydroxide) and without adjuvants. It has been shown that low endotoxic lipopolysaccharide contributes not only to enhance the immune response but also to stabilize vaccine immunogenicity during at least 1 year storage.

Relevance. Hemorrhagic fever with renal syndrome (HFRS) is a non-transmissible viral zoonosis widespread in Eurasia, and in Russia it occupies a leading position among zoonotic viral infections and one of the first places among all natural focal human diseases. Aim. Obtaining evidence of the safety, quality and efficacy of a polyvalent vaccine against HFRS as a result of its preclinical studies using scientific assessment methods that meet the requirements and rules of good laboratory practice. Materials and methods. For preclinical studies of the polyvalent vaccine against HFRS, the materials and methods were used in strict accordance with the requirements of the regulatory documents, as well as previously described methods used to control the vaccine at the technological stages of its manufacture. Results. The data obtained as a result of preclinical studies of the polyvalent vaccine agains HFRS indicate a high immunogenicity and stability of the vaccine, the absence of: acute and chronic toxicity, allergenic, immunotoxic and mutagenic, as well as toxic effects on the reproductive organs of animals, embryo development and offspring, born to females who received the vaccine within 20 days of gestation. Conclusion. The obtained results of preclinical studies comply with the requirements for immunobiological medical preparations designed for humans, and are the basis for conducting the 1st phase of clinical trials the polyvalent vaccine against HFRS.

Hantaviruses are highly pathogenic causative agents of hantaviral fevers, including hemorrhagic fever with renal syndrome, registered among people in countries of the Eurasian continent and a disease called «hantavirus pulmonary syndrome» – in the countries of North and South America. More recently, the spread of hantaviral diseases has been detected in Africa. There are still no drugs for specific antiviral therapy. The most promising method of dealing with hantaviral fevers is specific prophylaxis, that is, vaccination of the population against hantaviruses, which determine the endemicity of different territories. This review summarizes current data on existing and developed vaccines against hantaviral fevers.

The article deals with the problem of knowledge erosion as the result of data and information explosive growth. The conception of knowledge and knowledge core as a system of established and accepted scientific ("textbook") knowledge necessary to be transferred for sustainable social development is presented. The way of protecting knowledge core from destruction and unauthorized change is proposed with the use of Unified Electronic Educational Environment (UEEE) based on a set of learning objects constituting the Unified Bank of Learning Objects. Permitted blockchain algorithm as a basic means of protecting Unified Bank of Learning Objects is considered.

Addition of adjuvants is a generally recognized method of enhancing the immunogenicity of vaccines. There is a large variety of adjuvants, therefore the choice of an adjuvant is based on the comparison of adjuvants efficacy in animal models, as well as assessment of their safety and tolerability. There are many different groups of substances that may have adjuvant properties, but relatively little attention is paid to carbohydrate-based adjuvants, despite the fact that they are compatible with live vector vaccines, safe, well tolerated, and their production is not laborious. Thanks to these advantages the use of these particular adjuvants in combination with any type of vaccine, including vector vaccines and DNA vaccines, may be most appropriate and promising. This review examines various types of carbohydrate adjuvants and the mechanisms that determine their efficacy.

A data processing method is proposed for estimating the measurement error of scaled test scores; this involves scaling half-test raw scores to effective full-test raw scores and converting them to scaled test scores. It is shown that the method allows to estimate the measurement error with high accuracy. The proposed approach to data visualization involves the removal of the part of the data corresponding to the rarest values. In the case of very noisy data, this method helps to eliminate the contribution of atypical values and provides a significant increase in the visibility of scatter plots.