Introduction Live attenuated influenza vaccines (LAIVs) are being developed to protect humans against future epidemics and pandemics. This study describes the results of a double–blinded randomized placebo–controlled phase I clinical trial of cold–adapted and temperature sensitive H7N3 live attenuated influenza vaccine candidate in healthy seronegative adults. Objective The goal of the study was to evaluate the safety, tolerability, immunogenicity and potential shedding and transmission of H7N3 LAIV against H7 avian influenza virus of pandemic potential. Methods and Findings Two doses of H7N3 LAIV or placebo were administered to 40 randomly divided subjects (30 received vaccine and 10 placebo). The presence of influenza A virus RNA in nasal swabs was detected in 60.0% and 51.7% of subjects after the first and second vaccination, respectively. In addition, vaccine virus was not detected among placebo recipients demonstrating the absence of person–to–person transmission. The H7N3 live attenuated influenza vaccine demonstrated a good safety profile and was well tolerated. The two–dose immunization resulted in measurable serum and local antibody production and in generation of antigen–specific CD4+ and CD8+ memory T cells. Composite analysis of the immune response which included hemagglutinin inhibition assay, microneutralization tests, and measures of IgG and IgA and virus–specific T cells showed that the majority (86.2%) of vaccine recipients developed serum and/or local antibodies responses and generated CD4+ and CD8+ memory T cells. Conclusions The H7N3 LAIV was safe and well tolerated, immunogenic in healthy seronegative adults and elicited production of antibodies broadly reactive against the newly emerged H7N9 avian influenza virus. Trial registration ClinicalTrials.gov NCT01511419
Analysis of development influenza activity season 2010-2011 is presented. Significant participation of influenza A(H1N1)pdm09 virus and influenza B of Victoria lineage virus in the epidemic morbidity structure with minor participation ofA(H3N2) virus was revealed. The influenza viruses isolated in Russia according to antigenic properties were similar to the strains included in the vaccine composition. Drift variants of influenza A(H1N1)pdm09 viruses isolated in Astrakhan and St.-Petersburg were recognized using WHO CC in London as representatives of three new genetic groups.
Introduction:The global co-circulation of two influenza B virus genetic lineages known as B/Yamagata and B/Victoria may lead to a mismatch between the circulating virus and the strain recommended for use in influenza vaccines.Little is known about the protective efficacy of unmatched influenza B strains, especially when it comes to live attenuated influenza vaccine.The main purpose of this study was to demonstrate the viability of using live attenuated influenza vaccine developed on B/USSR/60/69 backbone to protect against heterologous influenza B challenge infection.Methods: To estimate the potential crossprotective activity of mono-and trivalent live attenuated vaccines based on B/Victoria or B/Yamagata genetic lineage virus against a heterological challenge, ferrets were given one dose of vaccine and then were challenged with influenza B virus.The ferrets were then monitored for clinical signs associated with influenza infection.Samples of the ferrets' airways were tested for the presence of the challenge virus.Results: Mono-and trivalent live attenuated influenza vaccines were shown to be safe and cross-protective against genetically different influenza B viruses based on virological and histological data and clinical signs.A lower titer of heterologous challenge virus in the airways of the vaccinated ferrets compared to mock-vaccinated animals inoculated with the challenge virus was detected.Interestingly, B/Victoria-based vaccines were more cross-protective compared with B/Yamagata-based vaccines.Conclusion: In the case of mismatches of B component of the trivalent live attenuated influenza vaccine and lineage of the circulating influenza B viruses, one of the options could be using trivalent preparation containing a B/Victoria lineage component.
Abstract The Omicron variant of SARS-CoV-2 has rapidly spread globally in late 2021 - early 2022, displacing the previously prevalent Delta variant. Before December 16, 2021, community transmission had already been observed in tens of countries globally. However, in Russia, the majority of reported cases at that time had been sporadic and associated with travel. Here, we report an Omicron outbreak at a student dormitory in Saint Petersburg between December 16 - 29, 2021, which was the earliest known instance of large-scale community transmission in Russia. Out of the 465 sampled residents of the dormitory, 180 (38.7%) tested PCR positive. Among the 118 residents for whom the variant has been tested by whole-genome sequencing, 111 (94.1%) carried the Omicron variant. Among these 111 residents, 60 (54.1%) were vaccinated or had reported previous COVID-19. Phylogenetic analysis confirmed that the outbreak was caused by a single introduction of the BA.1.1 sublineage of Omicron. The dormitory-derived clade constituted a significant proportion of BA.1.1 samples in Saint-Petersburg and has spread to other regions of Russia and other countries. The rapid spread of Omicron in a population with preexisting immunity to previous variants underlines its propensity for immune evasion.
In our study, 155 patients with chronic hepatitis B viral load was analyzed and its relationship with some of the results of laboratory and instrumental examinations. Found that half of the patients had a viral load of 4-5 log copies/ ml and above. In HBe-negative patients, the viral load is lower than in patients with HBeAg. The level of viremia had a direct correlation with the activity of ALT and AST, and eedback to the level of blood platelets. In patients with a viral load of more than 5 log copies / ml, significantly higher ALT, AST and GGT, as well as the level of red blood cells, whereas platelet counts were significantly lower than in patients with viremia <5 log copies/ml . Platelet counts inversely correlated with age. In 11% of patients with chronic hepatitis B over 40 years, had platelet counts below normal. The level of viral load and ALT and AST is straight, and the level of blood platelets inverse correlation with the severity of liver fibrosis. In patients without evidence of liver fibrosis (F0) viral load was significantly lower than in patients with signs of fibrosis of the liver at any stage of its formation.
Human seasonal coronaviruses (hCoVs) are a group of viruses that affect the upper respiratory tract. While seasonal patterns and the annual variability of predominant hCoV species are well-documented, their genetic and species diversity in St. Petersburg and across Russia remains largely unexplored. In this study, we developed a two-pool, long-amplicon (900-1100 bp) PCR primer panel for the whole-genome sequencing of four seasonal hCoV species. The panel was validated using nasopharyngeal swab samples collected within the Global Influenza Hospital Surveillance Network (GIHSN) project. Over a period of six epidemiological seasons from 2017 to 2023, we retrospectively analyzed 14,704 nasopharyngeal swabs collected from patients hospitalized in St. Petersburg clinics. Of these samples, 5010 (34.07%) tested positive for respiratory viruses, with 424 (2.88% of all samples) identified as seasonal human coronaviruses. The assessment of species diversity showed that predominant hCoV species alternate between seasons. Whole-genome sequences for 85 seasonal human coronaviruses (hCoVs) with >70% genome coverage were obtained, including 23 hCoV-OC43, 6 hCoV-HKU1, 39 hCoV-229E, and 17 hCoV-NL63. These represent the first near-complete genomes of seasonal hCoVs from the Russian Federation, addressing a significant gap in the genomic epidemiology of these viruses. A detailed phylogenetic analysis of the sequenced genomes was conducted, highlighting the emergence of hCoV-229E subclades 7b.1 and 7b.2, which carry numerous substitutions in the Spike protein. Additionally, we sequenced a historical hCoV-229E isolate collected in the USSR in 1979, the oldest sequenced 229E virus from Eurasia, and demonstrated that it belongs to Genotype 2. The newly developed PCR-based sequencing protocol for seasonal hCoVs is straightforward and well-suited for genomic surveillance, providing a valuable tool to enhance our understanding of the genetic diversity of human seasonal coronaviruses.
Despite the success in prevention and therapy, influenza remains a mass disease with mortality rate up to 0.01—0.2% worldwide.Purpose. Conducting clinical and laboratory analysis of influenza infection cases and evaluating their etiological significance in adult hospitalized patients during 2018—2019 epidemic season. Materials and methods. There were analyzed 569 case histories of patients hospitalized at the Clinical Infectious Diseases Hospital named after S.P. Botkin. Patients were examined by PCR that resulted in verified influenza virus in 260 cases. Nasopharyngeal swabs collected from 36 patients were examined by virological method on MDCK cell culture. 24 influenza virus strains were isolated and identified.Results. The study allowed to identify a viral landscape represented by influenza viruses A and B found in 98.5% and 1.5% cases, respectively. Influenza viruses isolated on cell culture in 50% of cases were identified. Among the influenza viruses isolated on cell culture there were identified serotype A influenza viruses (H1N1) closely related to the pandemic influenza A (H1N1)pdm09. Some isolates (41.7%) belonged to serotype A (H3N2), which were related to strain A/Singapore/16-0019/16. Influenza B virus strain of the Victoria lineage isolated from a hospitalized patient possessed a triple deletion in hemagglutinin gene, which antigenic properties substantially differed from those of the influenza virus strain being included into current influenza vaccines. Upon admission, the condition of most patients was estimated as moderate (males — 48.7%, females — 51.3%). The median patient age was 35 years old, with comorbidities being registered in 50% cases. The clinical picture for 2018—2019 seasonal influenza displayed no distinctive features as compared to previous epidemic seasons. The duration of intoxication and catarrhal syndrome was 4.3±0.13 and 6.9±0.29 days, respectively, with median body temperature ranging within 39.2±0.06°С. All patients received standard pathogenetic therapy. Complications were noted in 86.7% cases such as pneumonia — 11.1%, sinusitis — 6.9%, bronchitis — 56.9%. The bed day length was 5.93±0.29, no lethal outcomes were recorded.Conclusion. It was found that influenza A viruses were dominant in patients observed comprising up to 98.5% cases, whereas influenza viruses B were found in as few as 1.5% patients. The clinical picture was characterized by severe intoxication and catarrhal syndrome, being frequently associated with complications.
ABSTRACT In this paper, we analyze the etiology of the diseases occurring during two consecutive influenza epidemic seasons in St. Petersburg, Russian Federation. The analysis is based on the results of the PCR diagnostics of the clinical samples collected from patients hospitalized in three St. Petersburg hospitals with influenza like illnesses (ILI). It was shown that the influenza virus A(H1N1)pdm09 was the dominant causative agent during the 2012-2013 epidemic season while, in the 2013-2014 season, A(H3N2) virus was predominant among adults and children. The influenza B virus activity was high in the 2012-2013 season and low in the 2013-2014 season. During both seasons, the main causative agent for the hospitalization of young children was respiratory syncytial virus (RSV), followed by rhinovirus and influenza virus. The rate of involvement of parainfluenza, adenovirus, metapneumovirus and coronavirus was low and was negligible for bocavirus. Children 0-2 and 3-6 years old formed the group of patients that was affected by acute respiratory infection agents the most. Children younger than 3 months old were the major group of the intensive care unit (ICUs) patients and only 27.5% of them were adults. RSV and rhinovirus were the leading cause of ILI among the children admitted to ICU. Among the adult patients admitted to the ICU, only influenza A(H1N1)pdm09, A(H3N2) and B viruses were detected during both influenza seasons. According to the results of the antigenic and genetic analysis, most influenza A(H1N1)pdm09 and A(H3N2) viruses circulating in St. Petersburg matched the vaccine strains recommended by the WHO for vaccine composition in the 2012-2013 and 2013-2014 seasons.
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