(1) Background: Endothelial dysfunction is a key mechanism in the pathogenesis of COVID-19. High endothelin-1 during COVID-19 is associated with severe complications and increased mortality rates during hospitalization. This study is aimed to investigate the association of endothelin-1 levels with the risk of 30-day and 12-month all-cause mortality in patients with prior COVID-19. (2) Methods: A prospective study was conducted involving patients with COVID-19 in Karaganda, Kazakhstan. The level of endothelin-1 in the blood serum was evaluated by ELISA. Univariate and multivariate Cox regression was used to determine factors and significance of endothelin-1 associated with the risk of mortality within 30 and 365 days from hospitalization. (3) Results: The median endothelin-1 was higher in the group of patients who passed away within 30 days. The group showed statistically significant differences when compared to healthy volunteers from the control group (p = 0.0001), surviving patients (p = 0.001), and those who passed away within a year (p = 0.002). (4) Conclusions: Endothelin-1 levels are associated with increased mortality risk during the acute period of COVID-19, while plasma endothelin-1 level association with COVID-19 survivor mortality risk does not persist after 12 months.

Understanding the relationship between patient immune characteristics, disease severity, and mortality represents a critical step in the fight against COVID-19. Elevated levels of programmed death ligand-1 (PD-L1) and Neutrophil-lymphocyte ratio (NLR) are linked to increased severity of acute COVID-19 in patients. This study aimed to investigate the association of the combination of sPD-L1 and NLR with 1-year Mortality in patients with COVID-19. A prospective study was conducted involving patients with COVID-19 in Karaganda, Kazakhstan. The level of sPD-L1 in the blood serum was evaluated by ELISA. The effect of biomarkers on the development of mortality was analyzed with multivariate regression. The risk of mortality within one year HR was 2.46 if the plasma sPD-L1 value of more than 277.13 pg/ml, and for NLR more than 2.46 HR was 2.87. The model of combining sPD-L1 and NLR resulted in an improvement in the predictive accuracy of the Hazard Ratio 7.6 (95 % CI: 3.02-19.11). The combination of two immune-mediated markers (sPD-L1 and NLR), which reflect the systemic inflammatory balance of activation and exhaustion, can complement each other and improve the assessment of the risk of death in patients with COVID-19.

Aim: Current problem related to COVID-19 is various complications after disease, especially long-term mortality after COVID-19. Routine blood tests presented their effectiveness in the diagnosis, prognosis and mortality of COVID-19. The neutrophil-to-lymphocyte ratio (NLR) is an important marker of systemic inflammation. Soluble Trigger receptor expressed on myeloid cells-1 (sTREM-1) is considered an intrinsic enhancer of inflammatory signals. This study examined the predictive value of these markers in COVID-19 mortality. Methods: A prospective study was conducted involving patients with COVID-19 in Karaganda, Kazakhstan. The neutrophil–to-lymphocyte ratio (NLR) was calculated as the absolute number of neutrophils divided by the absolute number of lymphocytes. The level of sTREM-1 in the blood serum was evaluated by ELISA. Results: Plasma sTREM-1 concentration greater than 59.08 pg/mL and an NLR greater than 2.29 had an increased risk of early mortality (hazard ratio = 8.07; 95% CI: 1.03– 62.17 and 9.24; 95% CI: 1.202– 71.08, respectively); for long-term mortality of sTREM-1 greater than 47.34 pg/mL (hazard ratio = 7.96; 95% CI: 1.072– 59.18) and NLR greater than 2.10 (hazard ratio = 11.52; 95% CI: 1.551– 85.52). Conclusion: This study suggests that early levels of sTREM-1 and NLR are associated with the risk of 6-month mortality after experiencing COVID-19.

Influenza is especially dangerous for high-risk patients, for whom various vaccination strategies are used to prevent this disease. This study assessed the safety and immunological effectiveness of an inactivated trivalent polymer-subunit influenza vaccine Grippol® Plus administered according to two regimens in a group of 41 patients with severe progressive bronchopulmonary disorders. It also investigated the duration of vaccine-induced antibody response in this patient population. Group 1 of the study subjects (n = 21) received one dose of Grippol® Plus, and Group 2 (n = 20) received two doses of Grippol® Plus one month apart in the same influenza season. To measure antibody levels, paired sera were tested in hemagglutination inhibition assay pre-vaccination and at months 1 and 12 post-vaccination. Vaccine immunogenicity was assessed by the Committee for Medicinal Products for Human Use (CHMP) criteria. All patients were symptom-free in the post-vaccination period. The one-dose regimen met all CHMP criteria against strains A/California/7/2009(H1N1)pdm09-like and A/Texas/50/2012(H3N2) and the criteria for seroprotection and seroconversion against the B/Massachusetts/2/2012 strain. This regimen was associated with a significant increase in Ab titers against all the three influenza viral strains. In the two-dose group, no statistically significant differences were observed in IgG Ab levels, seroprotection rate, seroconversion rate or seroconversion factor at month 1 after the first and second vaccine doses. At month 12 post-vaccination, Ab levels returned to baseline, regardless the vaccination regimen. In lung transplant candidates, one-dose vaccination with an inactivated trivalent polymer-subunit influenza vaccine was effective in generating protective antibody levels for the current influenza season.

Introduction: COVID-19 has become the cause of a pandemic that has swept the entire world. Considering the genetic variability of the virus, the development and implementation of antiviral therapies, and the acquisition of a society's immune defenses through past infection or vaccination, the course of COVID-19 may change over time. The research aim was to study the prognostic significance of clinical and laboratory parameters with severe COVID-19 in 2020 and 2021 in Central Kazakhstan. Material and methods: A cohort of 1556 patients with COVID-19 admitted to the infection hospitals of Karaganda from May to July 2020 and 2021 year was retrospectively analyzed. The association of clinical and laboratory parameters with the severe disease was analyzed using univariate and multivariate logistic regression, and independent predictors were established for each factor. Results: The comparative analysis of the prognostic significance of demographic, clinical, and laboratory parameters in different periods of the pandemic showed a reduction in developing severe COVID-19 among hospitalized patients in 2021 compared to 2020. The essential value of comorbidity, especially chronic renal failure, and chronic heart failure remained significant against the background of decreasing prognostic significance of age, gender, and clinical and laboratory indicators of inflammation for the severe course of COVID-19.

Background: SARS-CoV-2 infection has raised concerns about altered immune responses, creating a need to evaluate influenza vaccine performance in the post-COVID period. This study aimed to compare the immunogenicity and safety of a quadrivalent inactivated subunit adjuvanted influenza vaccine in adults aged 18–85 years during the 2022–2023 season. Methods: A total of 144 adults were enrolled: group 1, aged 18–59 years (n = 124), and group 2, aged 60–85 years (n = 20). All received a quadrivalent inactivated subunit adjuvanted vaccine containing 5 μg of each influenza antigen and 500 μg of Azoximer bromide. IgG antibodies to vaccine strains were measured at baseline and days 30–32 using the hemagglutination inhibition assay. Participants were actively monitored for adverse events by telephone. Results: The Geometric Mean Fold Increase (GMFI) met the efficacy criteria in both age groups (≥2.5 for 18–59 years and ≥2.0 for 60–85 years), with no significant differences. The seroprotection rate reached accepted thresholds for most strains but was below criteria for B/Victoria in the 18–59 group (48%) and for B/Phuket in the 60–85 group (35%). Significant between-group differences were observed for B/Victoria (p = 0.01) and B/Phuket (p = 0.007). Seroconversion met criteria for all strains in younger adults, but for older adults, it was insufficient for B/Phuket (20%, below the ≥30% threshold; p = 0.05 vs. 18–59 years). Local reactions occurred in 24.2% and systemic in 11.3% of younger adults; in older adults, in 20% and 15%, respectively. All resolved spontaneously within 1–3 days. Conclusions: The quadrivalent adjuvanted influenza vaccine demonstrated acceptable immunogenicity and safety in adults aged 18–85 years despite potential post-COVID immune alterations.