Omsk hemorrhagic fever virus (OHFV) is a member of the tick-borne encephalitis virus (TBEV) complex of the Flaviviridae family. Currently, there are no data on the cross-reactivity of antibodies to the NS1 proteins of OHFV and TBEV. Such data are of major interest for monitoring viral encephalitis of unknown etiology due to the increasing geographical distribution of OHFV. In this study, a recombinant OHFV NS1 protein was produced using the Escherichia coli expression system and purified. The recombinant OHFV NS1 protein was recognized by specific mice immune ascetic fluids to the native OHFV NS1 protein. A Western blot analysis and ELISA of the recombinant NS1 proteins of OHFV and TBEV were used to study the cross-reactivity of antibodies from immune ascites fluid obtained from OHFV-infected mice and mAbs against TBEV NS1. Anti-TBEV NS1 mouse monoclonal antibodies (mAbs) have been shown to not be cross-reactive to the OHFV NS1 protein. Sera from patients with confirmed tick-borne encephalitis (TBE) were examined by ELISA using recombinant OHFV NS1 and TBEV NS1 proteins as antigens. It was shown for the first time that cross-reactive antibodies to the OHFV NS1 protein were not detected in the sera of TBE patients, whereas the sera contained antibodies to the TBEV NS1 protein.

Influenza is an acute highly contagious respiratory infection, caused mainly by influenza A, B and C viruses. Influenza is of particular importance among other infectious diseases, due to the high virulence of the pathogen, widespread distribution, and the ability to spread pandemic. However, at the present stage, serious changes are registered in the epidemic process of influenza. The leading in these processes undoubtedly belongs to the ongoing COVID-19 pandemic, as well as to other events directly related to this pandemic. This article highlights the current epidemiological characteristics of influenza infection during the COVID-19 pandemic, and considers the likely reasons for the development of such changes. Mass immunization against influenza, introduced according to WHO recommendations, has demonstrated convincing results: the use of influenza vaccines has reduced the risk of morbidity in healthy populations by 70-90%. Moreover, vaccination of the elderly reduces the number of serious illnesses and complications by 60% and deaths by 80%. This method of fighting influenza is also a priority in Russia.

Objectives: Antiretroviral (ARV) drugs have played a vital role in controlling the HIV-1 epidemic; however, some challenges remain. ARV drugs vary in their ability to control HIV infection, displaying differences in treatment-limiting factors and genetic barriers to resistance. The current report assesses the prevalence of HIV-1 drug resistance mutations (DRMs) among patients who failed first-line antiretroviral therapy (ART) and evaluates the genetic barrier of different regimens.Methods: The study cohort ( n = 271) included HIV-infected individuals who visited the Novosibirsk, Russia, HIV/AIDS clinic in 2018-2022. All patients received first-line ART prior to virological failure. Sociode-mographic and HIV-related data were collected from medical records and self-reported questionnaires. HIV-1 pol gene sequences were generated, and the presence of HIV-1 DRM was assessed. The genetic barrier to resistance was assessed by combining treatment regimen and adherence data.Results: Nonoptimal ART adherence was identified in 48.3% of patients and correlated with male sex, PWID, unemployment, and rural area residence. Most of the patients with high-level adherence were identified among those who were on TDF + 3TC + DTG. HIV-1 DRMs were identified in 54.6% of the patients. The analysis of HIV-1 DRM, ART regimen, and adherence data classified TDF + 3TC + DTG and TDF + 3TC + LPV/r as treatment regimens with a high genetic barrier, whereas EFV-containing ART was classified as a regimen with a low genetic barrier.Conclusions: The current study delivers results on the efficacy of HIV-1 ART and treatment adherence in real-world practice settings. This report suggests that ART regimens with a high genetic barrier to resistance combined with improved treatment adherence may reduce the transmission of HIV-1 resistant variants.(c) 2023 The Author(s). Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy.This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Omsk hemorrhagic fever virus (OHFV) is a member of the tick-borne encephalitis virus (TBEV) complex of the Flaviviridae family. Currently, there is no data on cross-reactivity of antibodies to the NS1 proteins of OHFV and TBEV. Such data are of major interest for monitoring viral encephalitis of unknown etiology due to the increasing geographical distribution of OHFV. In this study, recombinant OHFV NS1 protein was produced using Escherichia сoli expression system and purified. The recombinant OHFV NS1 protein was recognized by specific mice immune ascetic fluids to the native OHFV NS1 protein. Western blot analysis and ELISA of recombinant NS1 proteins of OHFV and TBEV were used to study the cross-reactivity of antibodies from immune ascites fluid obtained from OHFV-infected mice and mAbs against TBEV NS1. Anti-TBEV NS1 mouse monoclonal antibodies (mAbs) have been shown not to be cross-reactive to OHFV NS1 protein. Sera from patients with confirmed tick-borne encephalitis (TBE) were examined by ELISA using recombinant OHFV NS1 and TBEV NS1 proteins as antigens. It was shown for the first time that cross-reactive antibodies to OHFV NS1 protein were not detected in the sera of TBE patients whereas the sera contained antibodies to TBEV NS1 protein.

Materials and methods: a pilot open observational prospective study of 218 pediatric patients with laboratory-verified COVID-19 diagnosis was performed. The main epidemiological data were analyzed, including the age structure, as well as the features of the clinical course of this disease. The development of COVID-19 pneumonia was recorded in 11,5% of cases (25 patients), while more often pneumonia was recorded in children of the first year of life, as well as over 12 years of age (23,5% and 20% of cases, respectively) than in children of other age groups (p