Relevance. COVID-19 vaccination reduces mortality and the course of severe diseases. However, there is an insufficiency of studies evaluating factors leading to infection among COVID-19 vaccinated individuals.Aim. Identification of epidemiological features that distinguish cases of the disease in vaccinated and unvaccinated cohorts.Materials and methods. The analysis of the incidence of COVID-19 in 1126 hospitalized patients in the period from 23.06.2021 to 01.05.2022 was carried out taking into account the presence or absence of vaccination against the SARS-CoV-2 virus.Results. It was found that the risk of COVID-19 getting sick in the unimmunized was 1.5 times higher than in the vaccinated (p < 0.05). The incidence of hospitalization, due to the severity of the condition (moderate, severe and extremely severe), in unvaccinated people with no history of comorbidities, is more than 3 times higher than in vaccinated people (p < 0.05) in the same group. The probability of death from COVID-19 among vaccinated people is 1.5 times lower than among unimmunized people (p < 0.05). The age characteristic of mortality in vaccinated people shifts to the «senile» age (76.93 ± 1.32), while among the unimmunized, the age of death is closer to the category of «elderly» (73.74 ± 1.39 years) (p ≤ 0.05). In the structure of mortality among the vaccinated, the main share was made up of patients with a history of 3 to 7 concomitant systemic diseases (66.7%), while among the unvaccinated, the main share (74.5%) were patients either without comorbidities or with a history of 1 to 2 concomitant diseases.Conclusion. The results of the epidemiological features of the COVID-2 epidemic process have shown that vaccination against the SARS-CoV-2 virus is vital for elderly and senile people with comorbid conditions.

Relevance. Due to the large-scale vaccination campaigns against the SARS-CoV-2 coronavirus taking place worldwide, the question arises as to how vaccination may affect complete blood count (CBC) parameters in COVID-19 cases. Research objective: assess differences in complete blood count parameters in COVID-19 patients based on their vaccination status. Materials and methods. A review of publications was conducted describing and presenting the complete blood count parameters in patients with verified COVID-19, by stratifying them into vaccinated and unvaccinated individuals against the SARS-CoV-2 virus-caused disease. Subsequently, a meta-analysis of the results for each CBC parameter was carried out by describing identified differences among patients with mild and moderate COVID-19, lacking comorbidities affecting CBC indicators. Results. The analysis conducted allowed to determine that the complete blood count parameters do not exceed the reference range in most cases in both groups, excepting those of individuals with a severe disease course. The exception is the erythrocyte sedimentation rate (ESR) (42 [20.5–63.5] (∑n = 107, Me [Q1–Q3])) mm/h in unvaccinated individuals. Also, a slightly lower absolute lymphocyte count is observed in vaccinated individuals (0.95 [0.58–1.62] × 109/L (∑n = 441, Me [Q1–Q3])). There is a twofold greater range of leukocyte quartile values in vaccinated individuals compared to unvaccinated individuals: 7.07 [4.07–12.31] × 109/L (∑n = 555, Me [Q1–Q3]) vs 5.68 [4.02–8.34] × 109/L (∑n = 2202, Me [Q1–Q3]). A similar pattern is observed for monocytes. Conclusion. Conducting a meta-analysis of laboratory parameters in COVID-19 cases among vaccinated and unvaccinated individuals allows for determining the effectiveness of vaccination as well as identify the major trends in dynamic changes for essential blood parameters among unvaccinated and vaccinated individuals in general or with certain immunobiological preparations.

A prospective randomized observational study was conducted in cohorts of vaccinated and unvaccinated patients hospitalized in one of the Moscow hospitals and diagnozed with COVID-19 in the period from 06.23.2021 to 01.05.2022.The purpose of the study was to identify the epidemiological features of COVID-19 in vaccinated people and to present scientifically based data on the need for vaccination and its importance in stopping the epidemic process.Materials and Methods. The samples were studied in comparison for a number of indicators: age, clinical condition at admission, the presence and number of concomitant systemic chronic diseases as well as disease outcomes.Results. It was proven that the risk of COVID-19 morbidity in vaccinated people decreased by 1.5 times, mortality by 1.5 times, and hospitalization due to the severity of the condition by 3.1 times. The mortality risk among vaccinated patients shifted to older age (76.9 years), while among unvaccinated patients, the mortality risk was higher for older people (73.7 years), which indicates an increase in life expectancy of vaccinated people.

Background: There are no barriers for the SARS-CoV-2 and the entire population of the planet is exposed to this infection. Objective: To study gender and age differences in incidence among hospitalized patients with COVID-19. Methods: The analysis included 5629 inpatients with COVID-19 in one hospital for the period of 2020-2021, including 3106 (55.2%) women and 2523 (44.8%) men. They were divided into 5 age cohorts according to the WHO classification as well as by gender. For a comparative analysis of morbidity, a statistical correction of the age-sex composition (SCVS) of the city9s population was applied depending on the ratio of both men and women in age cohorts based on data from the Federal State Statistics Service. Results: The younger age group of men (18–44 years) had the highest risk for the incidence of COVID-19, who get sick more often (59.2%) than women (40.8%). In the older age group (60–74 years), the proportion of cases in men also larger than that in women (55.5% vs. 44.5%), and in the nonagenarian group (91–100 years), on the contrary, the proportion of women (54.3%) is higher than that of men (45.7%). Conclusion: To establish the true risk groups for COVID-19 morbidity, it is advisable to carry out calculations using SCVS as a statistical indicator of the ratio of men and women in different age categories for the administrative territory under study. It was found that young men (39.0 ± 5.0 years) had the maximum risk of getting COVID-19 (1.5 times higher) compared to young women.

There are increasing data concerning changes in hematological (clinical) and biochemical blood tests in patients with COVID-19 infection, which indicate the severity of the manifestations of the infectious process. Coagulopathy often correlates with the severity of COVID-19 disease and the risk of death. In this regard, prediction of developing coagulopathy and its prevention remain quite relevant. The aim of our study was to identify differences in the content of platelets and D-dimer in patients with COVID-19. The study included cohorts of patients vaccinated against SARS-CoV-2, and those not immunized against this infection. A prospective, randomized, observational study of the patients’ response was performed in cohorts of 588/52.2% vaccinated (vaccinated) and 588/52.2% non-immunized (non-vaccinated) patients with diagnosed COVID-19 over the period from 23.06.2021 to 01.05.2022. The levels of blood platelets and D-dimer, as well as clinical outcomes of the disease in patients with COVID-19, were studied in dynamics on days 1-2, 5-6 and 10-12 of hospitalization. Upon admission, the normal value of the blood platelet counts did not differ between the compared groups, being 206.58 × 109 in vaccinated group and 204.85 × 109 in the unvaccinated group, respectively. a moderate increase in the concentration of D-dimer was noted in both groups upon admission, i.e., 2838.60 ng/mL in the group of vaccinated patients and 3242.08 ng/mL among the unvaccinated patients. In the course of the study, we have shown that the dynamics of D-dimer index in vaccinated versus non-immunized persons was similar according to the days of disease, showing an increase from the first day and a trend towards an higher values, starting from 5-6 days. At the same time, the dynamics in the vaccinated patients was somewhat less favorable than that of the non-immunized subjects. In the patients who were not immunized throughout the entire observation period, the platelet count exceeds the levels found in vaccinated subjects, thus suggesting higher risk of thrombosis and cytokine storm. The data obtained show that the dynamics of D-dimer and platelet counts in vaccinated and non-immunized people is similar on appropriate terms of the illness. However, the changes are more pronounced in vaccinated cohort, but it does not indicate a greater risk of adverse outcomes.

Methicillin-resistant Staphylococcus aureus (MRSA) is the most common multiresistant agent of hospital acquired infections in Europe. Health care-associated infections caused by MRSA described of severe course, epidemic dissemination, often with fatal outcome, accompanied by considerable economic damage. The prevention of such diseases is devoted to many publications of research results. However, developed and implemented by some preventive measures demanded evaluation of their effectiveness. Thus, the sanitation of MRSA nasal carriers among medical staff, as a measure of prevention strategies hasn’t unique estimate. In the article presents the results, we conducted a meta-analysis to assess the effectiveness of intranasal decolonization of Staphylococcus aureus among medical staff. In the study materials includes the results of four randomized clinical trial, installed total relative risk (RR = 0.20; [95% ДИ = 0.06 - 0.66], = 22.72; df = 3; p = 0.0001),shows the effectiveness of decolonization nasal carriers Staphylococcus aureus, a reduction in the frequency of the carrier and the number sources of infection among medical staff within a 6 month period from the date of its holding.

Methicillin-resistant Staphylococcus aureus (MRSA) is the most common multiresistant agent of hospital acquired infections in Europe. Health care-associated infections caused by MRSA described of severe course, epidemic dissemination, often with fatal outcome, accompanied by considerable economic damage. The prevention of such diseases is devoted to many publications of research results. However, developed and implemented by some preventive measures demanded evaluation of their effectiveness. Thus, the sanitation of MRSA nasal carriers among medical staff, as a measure of prevention strategies hasn’t unique estimate. In the article presents the results, we conducted a meta-analysis to assess the effectiveness of intranasal decolonization of Staphylococcus aureus among medical staff. In the study materials includes the results of four randomized clinical trial, installed total relative risk (RR = 0.20; [95% ДИ = 0.06 - 0.66], = 22.72; df = 3; p = 0.0001),shows the effectiveness of decolonization nasal carriers Staphylococcus aureus, a reduction in the frequency of the carrier and the number sources of infection among medical staff within a 6 month period from the date of its holding.

The aspects of the epidemic process evolution of acute enteric infections in modern conditions are discussed in this paper. The frequency of diarrheal infections in general and in different seasons was evaluated according to the questionnaire survey of 2052 respondents in Kemerovo. Assessment of risk of acute intestinal infections among residents of different sex and age, and in different administrative areas of the city is represented. Risk factors, including the degree of home improvement, contact with patients in the community, the presence of domestic animals, the use of raw water for drinking, domestic use of water coolers, were assessed. We studied the risk of diarrheal diseases according to the food priorities of the respondents, place of food purchasing, the quality of food, and to the readiness of used dishes. Additionally the risk of diarrhea associated with the intensity of use of services catering was analyzed.