Abstract

The influenza virus is one of the most dangerous causative agents of respiratory diseases, and its study is important for epidemiological control, especially in the case of cocirculation with SARS-CoV-2. Comparative analysis of influenza viruses isolated from early and severe cases in epidemic seasons before and during the COVID-19 pandemic in Russia. The article is based on the results of monitoring the circulation of seasonal influenza viruses obtained in 2019–2023. Samples from early and severe cases of influenza were studied using real-time PCR and whole-genome sequencing. Antigenic characterization of isolated viruses was carried out, and their sensitivity to antiviral drugs was studied. The flu season of 2019–2020 in Russia was the last epidemic season before the COVID-19 pandemic with the predominant cocirculation of influenza B and influenza A/H1 N1 pdm09 viruses. After the onset of the pandemic in the 2020–2021 season, the influenza virus was practically absent in Russia and was detected sporadically. Virus circulation resumed in the 2021–2022 season with dominance of A/H3N2 (clade 3C.2a1b.2a2) and continued in the 2022–2023 season with the dominance of A/Hi N1 pdm09 (clade 6B.1A.5a.2a) and the spread of influenza B/Victoria viruses (clade V1A.3a.2), which were antigenically different from the viruses circulating before the COVID-19 pandemic. Genetic analysis of the D222G/N mutations in the hemagglutinin of the A/H1N1pdm09 viruses, which are associated with increased disease severity, revealed an approximately equivalent selection of the D222G and D222N mutations in the 2019–2020 season and increased occurrence of the D222N variant in the 2022–2023 season. Cocirculation with SARS-CoV-2, the return of influenza circulation to epidemic levels, the emergence of new antigenic variants and pathogenicity factors emphasize the need to monitor and study influenza viruses for epidemiological analysis and prognosis, as well as for the development and application of effective measures to protect the population.

中文翻译：

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俄罗斯COVID-19大流行之前和期间（2019-2023年）流行季节早期和重症病例中分离出的流感病毒的比较分析

摘要

流感病毒是呼吸道疾病最危险的病原体之一，其研究对于流行病学控制具有重要意义，特别是在与 SARS-CoV-2 共循环的情况下。俄罗斯 COVID-19 大流行之前和期间从流行季节早期和重症病例中分离出的流感病毒的比较分析。本文基于2019-2023年获得的季节性流感病毒传播监测结果。使用实时 PCR 和全基因组测序对早期和严重流感病例的样本进行了研究。对分离的病毒进行了抗原表征，并研究了它们对抗病毒药物的敏感性。俄罗斯 2019-2020 年流感季节是 COVID-19 大流行之前的最后一个流行季节，主要是乙型流感和甲型/H1 N1 pdm09 流感病毒共同传播。2020-2021年流感季爆发后，俄罗斯境内几乎不存在流感病毒，只是零星检测到。病毒传播在 2021-2022 年季节恢复，以 A/H3N2（进化枝 3C.2a1b.2a2）为主，并在 2022-2023 年季节继续，以 A/Hi N1 pdm09（进化枝 6B.1A.5a.2a）为主。乙型/维多利亚流感病毒（进化枝 V1A.3a.2）的传播，其抗原性与 COVID-19 大流行之前传播的病毒不同。对 A/H1N1pdm09 病毒血凝素中的 D222G/N 突变（与疾病严重程度增加相关）进行的遗传分析显示，2019-2020 年季节 D222G 和 D222N 突变的选择大致相同，并且 D222N 变体的发生率有所增加2022-2023 赛季。与 SARS-CoV-2 的共循环、流感循环恢复到流行水平、新的抗原变异和致病因素的出现，强调了监测和研究流感病毒以进行流行病学分析和预后以及开发和应用的必要性。采取有效措施保护民众。