Relevance. During a pandemic, the epidemiological well-being of the population of the whole world depends on the vaccination of each individual person, as cells of the immune layer. Only reliable and open information about adverse events after the use of vaccines, obtained in a timely manner in the process of continuous monitoring, can support the confidence and adherence of the population to vaccination.

Aim. To assess the monitoring system for AEFI (Adverse Events Following Immunization) in the Russian Federation and other countries.

Materials and methods. A descriptive epidemiological study was conducted with a review of regulatory and methodological documents, forms of federal statistical observation, information from the AIS «DRAID» (Analytical Information System «Department of registration and accounting of infectious diseases» program in Moscow, acts of investigation of post-vaccination complications, which were carried out by specialists from the branches of the Center for Hygiene and Epidemiology in Moscow, sources: eLIBRARU.ru, cyberleninka.ru, information from WHO’s websites, Internet resources for monitoring AEFIs in different countries and websites of manufacturers of COVID-19 vaccines, instructions for vaccines.

Conclusion. Thus, it is almost impossible for an epidemiologist working in one of the departments that participates in the monitoring of AEFIs to conduct a full-fledged prospective and retrospective epidemiological analysis and draw unambiguous conclusions about the AEFIs based only on data from open sources and forms of state statistical observation. There is a need for interaction and exchange of information between the subjects of monitoring.

Relevance. In a pandemic, studies on the duration of immunity in those who have recovered from COVID-19 and the formation of resistance to a new coronavirus infection are of particular importance.

Target. To study the retention time of IgG in the blood serum of employees of a medical institution who recovered from a new coronavirus infection COVID-19.

Materials and methods. The assessment of the timing of the formation of IgG was first carried out 3 weeks after the illness in employees of The National Medical Research Center for Otorhinolaryngology from April 2020 to December 2020. Further, the intervals for blood sampling to study the dynamics of antibodies to coronavirus infection were 3–4 weeks (9 blood samples for each ). Antibodies were examined by ELISA; immunological method for determining IgG (test system – "Vector Best", semi-quantitative analysis). Statistical processing of the study results was carried out using the SPSS-22 statistical software package and the OpenEpiver statistical calculator. 3.

Results and discussion. The proportion of employees of a medical institution who recovered from COVID-19 was 39%, among them persons aged 36 to 55 years prevailed. It was found that class G immunoglobulins persist from seven months or more in 56.3% of those participating in the observation (the positivity coefficient is much higher than 1.2), in about 12.7% of those who had been ill, IgG in the blood serum persisted for about six months, in 11, 3% about three months. There were no statistically significant differences in the duration of immunity between men and women.

Conclusion. A statistically significant direct relationship was found between age and the duration of immunity. 

Relevance. Vaccination is being replaced by the primary and most effective means of protecting the world's population from a new coronavirus infection.

Aim. Evaluation of the effectiveness of COVID-19 immunization in Saint-Petersburg.

Materials and methods: We retrospectively studied the epidemiological data on the cumulative incidence of COVID-19 in St. Petersburg among adults vaccinated (1,558,030 people) and unvaccinated (2,863,050 people) for period from December 01, 2020 to November 30, 2021 on 12.01.2021. We analyzed the data presented in the Federal Register of Persons with COVID-19 and the Federal Register of Those Vaccinated against COVID-19.

Results. The risk of COVID-19 infection among vaccinated is statistically significantly lower than among unvaccinated RR = 0.11 (95% CI 0.109–0.110; p < 0.001). Infected COVID-19 Vaccinated patients were less likely to need for emergency care/hospitalization RR = 0.30 (95% CI 0.29–0.30; p < 0.001). Also among the vaccinated mortality was lower RR = 0.35 (95% CI 0.33–0.37; p < 0.001).

Conclusion: We have established reliable preventive effectiveness of the use of domestic vaccines by reducing morbidity, the frequency of development of forms of the disease requiring inpatient treatment; reducing mortality among vaccinated and, accordingly, reducing the burden on the healthcare system of St. Petersburg.

Relevance. The effectiveness of vaccination of the working population against COVID-19 in the Russian background has not been studied enough.

Aim. To evaluate the effectiveness of vaccination of the working population with Gam-COVID-Vak (Sputnik V) in the Russian Railways as an example.

Materials & Methods.The effectiveness of vaccination with Sputnik V among employees of Russian Railways in the period from January 21 to November 31, 2021 was performed with the Cox regression method.

Results. The effectiveness of Sputnik V against COVID-19 infection with was 97.8% (95% CI 97.8–97.9%) for two doses, 91.9% (95% CI 91.6–92.2%) for a single dose, and 97.9% (95% CI 97.6–98.1%) for revaccination, all after socio-demographic factors adjusted. The effectiveness of vaccination against COVID-19 with hospitalization was 97.5% for two doses of Sputnik V (95% CI 97.1–97.9%), 86.1% (95% CI 83.7–88.1%) for a single dose, and 98.2% (95% CI 96.3–99.2%) for revaccination. The effectiveness against lethal COVID-19 was 95.2% (95% CI 93.1–96.6%) for two doses of Sputnik V and 94.8% (95% CI 89–97.6%) for one dose. The high efficiency of vaccination could be associated with a fairly young age composition of the employees of the Russian Railways.

Conclusions. The study showed the high effectiveness of vaccination with Sputnik V against COVID-19 among the working population.

Relevance. COVID-19 pandemic predetermines the relevance of the analysis of clinical and epidemiological peculiarities in different periods of morbidity growth in the pediatric population.

Aim. To identify clinical and epidemiological features of the course of COVID19 in Moscow among children (2020–2022).

Materials and Methods. The retrospective clinical and epidemiological analysis of the incidence of COVID-19 among children in Moscow over a two-year period (March 9, 2020 to March 30, 2022) was performed. We used data from case histories of 3092 children diagnosed with U07.1, hospitalized in infectious diseases departments for children with COVID-19 at Bashlyaeva Children's Clinical Hospital of Moscow and materials from Rospotrebnadzor report No 970 «Information about cases of infectious diseases in persons with suspected new coronavirus infection», information portal Stopcoronavirus.rf and others. The presence of SARS-CoV-2 RNA was confirmed by real-time reverse transcription polymerase chain reaction.

Results. Five upsurges of morbidity differing by clinical and epidemiological manifestations of the course of COVID-19 were distinguished. In the first period of morbidity rise (March–June, 2020) the age groups 7–14 and 14–17 years prevailed, in the fifth period (January 2022–March 2022) infants and young children prevailed. The most frequent severe and critical forms of COVID-19 were registered in the genovariate delta due to lung lesions, less frequently in the omicron strain. Comorbid pathology in children during all periods of the pandemic was a risk factor for severe course and unfavorable outcome of the disease. In general, the number of children hospitalized in intensive care unit (ICU) decreased: 3.7%. 4,7%, 4,7%, 3,3%, 3,2%. Administration of viral neutralizing monoclonal antibodies to SARS-CoV-2 to children at risk for severe disease during the fourth and fifth waves of COVID-19 reduced the number of children hospitalized in the ICU, despite the high morbidity rise than in the previous waves of COVID-19.

Conclusion. Each of the five identified COVID-19 morbidity bursts among children had its own features. The proportion of severe infection among hospitalized children was 3.7%, 4.7%, 4.7%, 4.7%, 3.3%, 3.3% according to the waves of morbidity rise. During the first two waves of COVID-19, the disease occurred as acute respiratory infections (80%). In the second wave, the proportion of children hospitalized in the ICU with a multisystem inflammatory syndrome reached 57.6%. In the third wave of COVID-19 there was an increase in the number of cases of bilateral viral pneumonia (34.8%), severe forms of pneumonia (CT-3-4) in children with comorbid diseases. In the fourth period the structure of hospitalized children in the ORIT was 72.3% of children from the risk group. During the fifth wave of COVID19, the number of infants and young children hospitalized increased (49%) in the early period of admission from the onset of the disease (44%).

Relevance. To date, the specific prevention of plague remains the most effective measure to prevent to prevent the deterioration of the epidemiological situation for this especially dangerous infection in the territory of the Russian Federation. The development of new vaccine preparations created on the basis of avirulent strains of Yersinia pestis with specific genetic defects, can play a crucial importance in the issues of plague immunoprophylaxis.

Aim. Determination and comparative analysis of the genomic organization of avirulent strains Y. pestis I-1, Y. pestis I-3536 and vaccine strain Y. pestis EV line NIIEG.

Materials and methods. The features of the genetic structure of three Y. pestis strains were studied using plasmid screening and whole genome sequencing.

Results and discussion. It was found that the Y. pestis I-1 and Y. pestis I-3536 strains, like Y. pestis EV, lack the chromosomal pgm region. Analysis the genome sequence of Y. pestis I-1 showed that this strain is devoid of the plasmid pMT1, while its individual genes were found in the chromosome structure and the unique 340 kb plasmid. It was revealed that the Y. pestis strain I-3536 lost the plasmid pCD1, however, fragments homologous to this plasmid were found in the structure of its genome.

Conclusion. The data obtained allow us to recommend Y. pestis I-1 and Y. pestis I-3536 as the basis for the development of a modern live attenuated plague vaccine.

Relevance. The search for informative markers for assessing the immunological efficacy of a live plague vaccine remains an urgent scientific task. The goal of the study

Aims was to make a comparative assessment of the level helper T-cells activation by CD69 and HLA-DR markers, in people, vaccinated against plague, in an in vitro test, using the disintegrated by ultrasonic Y. pestis cells, grown at temperature 28 °C as a specific stimulator.

Materials & Methods. A cytofluorimetric analysis of blood samples of 45 individuals vaccinated against the plague was carried out. The dependence of the result of cytological analysis of the two studied cell markers on the immunoregulatory index (IRI) of the vaccinated donor at the time of vaccination was revealed.

Results. It was found that for newly vaccinated individuals, the T-helpers were more intensive and prolonged by the early activation marker, while for those revaccinated with the immunoregulatory index, at the time of vaccination more than 1.5, the more intense cellular response was by the late activation marker.

Conclusions. Thus, the possibility of quantitative evaluation of the immunological efficacy of vaccination against plague, based on the identification of lymphocyte activation markers when stimulated with a specific antigen, is confirmed.

Relevance. The need to create a domestic pneumococcal polyvalent vaccine is one of the main directions of the «Strategy for the development of vaccine prevention of infectious diseases for the period up to 2035».

Aim. To evaluate the immunological efficacy and safety of the pneumococcal polysaccharide conjugate adsorbed thirteen-valent (PCV13) vaccine in the immunization of adults and children in theRussian Federation.

Materials and methods. The immunological efficacy and safety of the pneumococcal polysaccharide conjugated adsorbed thirteen-valent vaccine were studied in a prospective comparative randomized double-blind study in parallel groups in adult volunteers aged 18 to 65 years and a multicenter open comparative study in parallel groups in young children. In a clinical study of adults, 60 volunteers were randomized into two groups according to the 1:1 scheme (groupI, n = 30; group II, n = 30). A clinical study in children included 119 volunteers aged 15 months who were divided according to the 1:1:1 scheme (group I, n = 39; group II, n = 40; group III, n = 40). The reference vaccine in both studies is Prevenar® 13 (Pfizer Inc., USA).

Results. A clinical study in adults showed no statistically significant difference between the study groups according to the results of primary (the proportion of volunteers whose concentration of serotype-specific IgG to each of the 13 pneumococcal serotypes is equal to or exceeds the level of 0.35 mcg/ml (p > 0.039) before vaccination and 4 weeks after vaccination) and secondary criteria for evaluating effectiveness. Thus, the results obtained indicate a comparable level of immunogenicity of PCV13 with the comparison drug Prevenar®13 with a single intramuscular injection to healthy volunteers aged 18–65 years. Safety in both groups was comparable, 15 local reactions were registered, including 7 in group I volunteers who received the test drug, and 8 in comparison group volunteers. There were no statistically significant differences in the frequency of registered adverse events between the groups. Similar results were obtained with the immunization of children. For all 13 serotypes of the new PCV13 in relation to the reference drug, both primary and secondary criteria for assessing immunogenicity during immunization of children have been achieved (Difference ≤ 10% and GMC and GMT Ratio ≥ 0.5, respectively), which proves no less effectiveness of the pneumococcal polysaccharide conjugated adsorbed thirteen-valent vaccine compared with the reference vaccine Prevenar® 13. During the clinical study, a total of 27 adverse events were registered in children, which were associated with the introduction of vaccines and were represented by local and systemic reactions (5 AEs in study participants from group I (5/39) 12.80%, 18 AEs in study participants from group II (18/40) 45.0% and 4 AEs in study participants from group III (4/40) 10%). No SAEs were registered in this study.

Conclusion. The obtained results of the researches in children and adults allow us to recommend the preparation pneumococcal polysaccharide conjugate adsorbed thirteen-valent vaccine for immunization in order to prevent pneumococcal infection, both adults and children according to the 2+1 scheme within the National vaccination schedule and the calendar of preventive vaccinations according to epidemic indications of the Russian Federation.

Relevance. Patients with diabetes mellitus have an increased risk of developing various infections, including those of the lower respiratory tract. Immunization with anti-pneumococcal vaccines reduces pneumonia-related hospitalizations and deaths.

Aim. Evaluate the cost-effectiveness of vaccination against pneumococcal infection in 40and 65-year-old patients with type 2 diabetes mellitus (DM2).

Material and methods. The analysis was carried out from the perspective of the healthcare system. The Markov model based on Russian epidemiological data, taking into account the results of foreign studies, was used. Vaccination schedules with 1 dose of 13-valent pneumococcal conjugate vaccine (PCV13) followed by 1 dose of pneumococcal 23-valent polysaccharide vaccine (PPV23) and vaccination with only 1 dose of PCV13 were evaluated. The time horizon of the study is 5 years. Costs and life expectancy were discounted by 3.5% per year.

Results. Vaccination of 65-year-old patients with type 2 diabetes is characterized by extremely high cost-effectiveness (the incremental cost effectiveness ratio – ICER – for PCV13+PPV23 vaccination is 189.27 thousand rubles/QALY, and PCV13 vaccination entails a cost reduction of 371.92 rubles per 1 vaccinated). When vaccinating 40-year-old patients, the ICER for PCV13 + PPV23 vaccination is 491.31 thousand rubles/QALY, and for PCV13 – 55.31 thousand rubles/QALY.

Conclusion. Vaccination against pneumococcal disease in 40and 65-year-old patients with DM2 reduces the associated morbidity and mortality and is highly cost-effective. Compared to PCV13 vaccination alone, vaccination with PCV13 followed by the introduction of PPV23 provides an increase in the number of prevented cases of the disease and the deaths caused by it, but at the same time requires additional costs.

Relevance. Pneumococcal infection (PI) is one of the leading causes of disability and death of older people worldwide. In the Astrakhan region, as in other regions of the Russian Federation, there is a low coverage of pneumococcal vaccination (PV) and amounts to 1.3% of the adult population. This study reflects the regional problem of PV, an evaluation of its effectiveness in reducing exacerbations and the development of community-acquired pneumonia (CAP) in patients with COPD. The impact of pneumococcal infection (PI) in the development of pneumonia turned out in the period of the COVID-19 pandemic so far to be the most significant.

Aim of this work was to evaluate the level of doctor’s awareness in the issues of pneumococcal vaccination, as well as the results of its implementation in patients with COPD during COVID-19 pandemic.

Materials and methods. The study was conducted in the form of a survey in the period from October 2021 to February 2022. A survey was conducted through a questionnaire poll in polyclinics and pulmonology departments of multidisciplinary hospitals in Astrakhan. A total of 201 doctors and 173 patients suffering from COPD participated in the study. The doctors' responses were compared with the results of the survey conducted in 2018.

Results. This study shows that 26% of the surveyed patients with COPD were vaccinated with pneumococcal vaccine. Analysis of clinical effects after vaccination shows that exacerbations of COPD were absent during the year in 51.1% of vaccinated patients, and 35.2% in non-vaccinated group. The prevalence of CAP in vaccinated patients was 13.3% vs 32.4% in patients who did not receive vaccination.

Conclusion. This study showed a significant level of clinical efficacy of PV, characterized by a reduced incidence of COPD exacerbations and the development of VP in vaccinated patients, as well as a lower number of hospitalizations. Vaccinated patients reported mild severity of coronavirus infection, which determines the high prospects for further PV research as one of the important measures to counteract the COVID-19 pandemic. The problem of awareness in specialists about pneumococcal vaccination requires further improvement of educational programs on the relevant topic in the framework of continuing medical education. 

Relevance. Seasonal flu vaccination is still the most effective way to protect against flu viruses and help to reduce the burden of flu illnesses. Another possible benefit is the impact of yearly vaccines on severity of breakthrough infection. In this regard, the issue of choosing safe vaccine with high immunogenicity becomes relevant.

Aims. To evaluate the prophylactic efficacy of inactivated seasonal flu vaccines (quadrivalent subunit vaccine with adjuvant and trivalent vaccine) and reactogenicity of quadrivalent vaccine.

Materials and methods. 491 cases were included in our study: 152 cases received adjuvanted quadrivalent subunit flu vaccine «Grippol Quadrivalent», 118 cases received trivalent inactivated flu vaccine and 221 cases who have received no vaccinations during 2018–2019 epidemic season.

Results. inactivated vaccines showed high prophylactic efficacy in preventing seasonal influenza. Incidence of influenza and other viral respiratory disease cases was lowest in «Grippol Quadrivalent» group. Breakthrough influenza cases in individuals vaccinated with inactivated vaccine were predominantly mild, no severe cases were reported. The early post-vaccination period in «Grippol Quadrivalent» group showed no variation in adverse events with other vaccines.

Conclusion. Adjuvanted quadrivalent subunit flu vaccine was the most efficacious in preventing influenza in 2018–2019 epidemic season.

Relevance. The production and quality control of any drugs are strictly regulated. In the case of antiviral vaccines, the requirements for their safety and protective activity are getting tougher every year. Vaccine manufacturers face three tasks: ensuring high immunogenicity, safety and availability of the drug. During the development and production of immunobiological drugs, manufacturers must demonstrate sufficient purification from technological impurities to ensure the purity of the drug. Technological impurities directly depend on the technological process and the expression systems used. The Vero cell line has been widely used in the production of various antiviral vaccines for many decades. Thus, the improvement of technological processes for the purification of vaccine preparations from proteins and DNA of Vero cells is still matter of current interest.

Aims. Selection of resins and reagents for ion exchange chromatography to reduce the amount of technological impurities in the inactivated polio vaccine production.

Materials and Methods. To obtain viral suspensions, producer cultures were infected with poliovirus type 1 (Sabin strain LSc 2ab), type 2 (Sabin strain P712 Ch 2ab), and type 3 (Sabin strain Leon 12a1b). Multiplicity of infection was 0.02 ± 0.01 TCD50/cell. To evaluate the efficiency of ion-exchange chromatography we determined the degree of purification of fractions from ballast proteins, the degree of purification of fractions from residual cellular DNA, and the degree of extraction of the target antigen using specific formulas.

Results and discussion. More than 80 experiments have been performed to purify type 1, type 2, and type 3 poliovirus concentrates using various sorbents. In quality control of purified concentrates of type 1, type 2 and type 3 polioviruses, in addition to analysis for total protein, an analysis was performed for the presence of Vero cell proteins.

Conclusion. The use of the proposed modifications of purification of concentrates of Sabin strains of poliovirus types 1, 2 and 3 using ion exchange chromatography allows to obtain inactivated viral products that meet the requirements of WHO and the European Pharmacopoeia both in biochemical parameters (the content of host-cell DNA and the content of ballast proteins, including host-cell proteins) and specific activity (D-antigen content). Furthermore, additional purification of vaccines using ion exchange chromatography allows to reduce the content of residual cellular DNA to almost zero, which makes the inactivated polio vaccine the most attractive for its inclusion in various combined vaccines.

The article discusses the residual effects of survivors of COVID-19, referred to as long-term covid, a short list of their manifestations, their possible causes and difficulties of recognition. Changes in the primary structure of emerging coronaviruses from the Wuhan strain to new omicron strains are analyzed. Among the features of their evolution, there is an increase in the content of arginine and lysine, especially in the S1 subunit, and a decrease in the proportion of aspartic and glutamic amino acids. The receptorbinding domain of omicrons is characterized by a tendency to decrease the content of threonine, serine and glutamine. Mutations in the S protein are characterized by asymmetry in relation to both substitutable and substitutive amino acids. Isoleucine and cysteine are not replaced. Certain trends and limitations in the mutations of their S protein and especially the unusual ratio transversion: transitions in them argue for the version of the artificial origin of the SARS-Cov-2 variants. At the level of the S protein genes, there are prohibitions regarding the use of certain codons. To assess the effectiveness of vaccines and the sensitivity of coronaviruses to them during a pandemic, it is useful to divide pandemic coronaviruses into two groups: omicrons and pre-omicrons. This division is justified by the fact that these groups differ sharply in the number of mutations and changes in the composition of immune epitopes, especially in the receptor-binding domain. The specific tendency of changes in its amino acid composition, apparently, is associated with a consistent decrease in pathogenicity in BA.1, BA.2, BA.4 and BA.5 variants. Taking into account these features makes it possible to predict the sensitivity of coronavirus strains to the vaccines used and rationally design vaccines with a wide range of specificity.

Objective. Of particular interest is the incidence of COVID-19 in closed groups, in institutions, in particular, in nursing homes, geriatric centers, veterans' homes and neuropsychiatric boarding schools.

Methods. Analysis and description of COVID-19 foci in closed long-term care facilities was carried out using literature sources from the MEDLINE medical information database using the PubMed electronic search engine, using the search query CARE HOME OR NURSING HOME OR LONG-TERM CARE FACILITY AND COVID-19 AND OUTBREAK. The share of sick people as a percentage of the total number of residents and individual employees was considered only in those publications that described the outbreak of COVID-19 in a single institution. The absence of data on the number of hospitalizations and deaths, symptoms, and data on the time frame of the outbreak was not an exclusion criterion, but their presence was taken into account in the analysis. We selected mainly publications where people with a positive PCR test for SARS-CoV-2 RNA were considered to be ill with COVID-19. However, it is worth considering that the authors describe outbreaks during the first rise in the incidence of COVID-19 in the world, when there was a shortage of test systems for a new coronavirus infection.

Results. An overview of the incidence of COVID-19 in the world in closed long-term care institutions is presented. It has been shown that residents of closed communities are elderly people with many concomitant diseases, in connection with which a severe course of COVID-19 and high mortality are often noted.

Conclusion. Convictions about the need to strengthen the quality of anti-epidemic measures in closed long-term care institutions, which are at risk, are summarized.