scholarly journals Characterization of influenza A(H1N1)pdm09 viruses in Germany in season 2019-2020 – co-circulation of an antigenic drift variant

Author(s):  
Marianne Wedde ◽  
Djin-Ye Oh ◽  
Silke Buda ◽  
Andrea Thürmer ◽  
Sandra Kaiser ◽  
...  

Background Influenza A(H1N1)pdm09 virus entered the human population in 2009 and evolved within this population for more than ten years. Despite genetic evolution no remarkable changes in the antigenic reactive pattern of these viruses were observed so far. Methods Primary respiratory samples of the German influenza virological sentinel were investigated by qPCR. Influenza virus-positive samples were characterized genetically and antigenetically. Results In December 2019, a antigenic drift variant characterized by an N156K substitution in the hemagglutinin of influenza A(H1N1)pdm09 virus emerged in Germany, which exhibited a reactivity to ferret antiserum that was an average 6 log2 lower than the vaccine virus A/Brisbane/02/2018 and the other A(H1N1)pdm09 viruses circulating in the influenza season 2019-2020. These viruses accounted for 20% of all A(H1N1)pdm09 viruses characterized in the German influenza sentinel. Patients infected with these viruses had a shorter median time period of medical consultation after onset of symptoms and were more frequently treated with neuraminidase inhibitors in comparison to patients infected with other A(H1N1)pdm09 viruses. Conclusions This parallel circulation of two antigenic variants of A(H1N1)pdm09 viruses which differ remarkably in their antigenic reactive pattern contributes to a greater variability in circulating influenza viruses and challenges vaccination.

2020 ◽  
Vol 25 (2) ◽  
pp. 65-77
Author(s):  
Natalia V. Breslav ◽  
Kirill G. Krasnoslobotsev ◽  
Evgeniya A. Mukasheva ◽  
Elena S. Kirillova ◽  
Alexandra G. Rosatkevich ◽  
...  

BACKGROUND: The article presents the results of studying the effectiveness of anti-influenza drugs in Russia in the period 20172020. The sensitivity of circulating strains of influenza viruses A(H1N1)pdm09, A(H3N2) and B to neuraminidase inhibitors oseltamivir, zanamivir and rimantadine was determined. The analysis of scientific articles by both domestic and foreign researchers on new promising chemotherapy drugs for influenza viruses was carried out. AIMS: study of the sensitivity of influenza viruses circulating strains to specific anti-influenza drugs in the framework of monitoring in the period 20172020. MATERIALS AND METHODS: The study was conducted within the framework of epidemiological surveillance of the influenza viruses circulation using the collection of the influenza etiology and epidemiology laboratory with the following criteria for selecting strains isolated from pregnant women, patients with complicated flu infection and severe acute respiratory infection (SARI), lethal outcomes, as well as patients undergoing treatment with specific drugs. Virological, immunological, and molecular genetic methods were used in the study, and following drugs substances were used: oseltamivir carboxylate, zanamivir, and rimantadine. RESULTS: For the period 20172020, the sensitivity of 541 influenza A and B viruses epidemic strains to anti-influenza drugs was studied. Most of the studied strains remained sensitive to neuraminidase inhibitors. The exceptions were: in 2017/2018 5 strains of the influenza A(H1N1)pdm09 virus resistant to oseltamivir and 2 strains of the influenza B virus, one with reduced sensitivity to oseltamivir, the second to zanamivir; in 2019/2020 influenza A(H1N1)pdm09 virus strain with reduced sensitivity to both drugs. In the 2018/2019 season, an influenza A/Moscow/246/2018 A(H1N1)pdm09 strain was found to be sensitive to rimantadine. CONCLUSIONS: The main and most common genetic markers of influenza viruses resistance to specific drugs are: for oseltamivir substitution H274Y in the influenza A(H1N1)pdm09 virus NA; for rimantadine substitution S31N in the influenza A(H1N1)pdm09 and A(H3N2) viruses M2 protein. Taking into account the low frequency of strains with reduced sensitivity to drugs with antineuraminidase activity, can confidently approve that they remain the drugs of choice for the treatment and prevention of influenza infection.


2014 ◽  
Vol 63 (12) ◽  
pp. 1626-1637 ◽  
Author(s):  
Mara L. Russo ◽  
Andrea V. Pontoriero ◽  
Estefania Benedetti ◽  
Andrea Czech ◽  
Martin Avaro ◽  
...  

This study was conducted as part of the Argentinean Influenza and other Respiratory Viruses Surveillance Network, in the context of the Global Influenza Surveillance carried out by the World Health Organization (WHO). The objective was to study the activity and the antigenic and genomic characteristics of circulating viruses for three consecutive seasons (2010, 2011 and 2012) in order to investigate the emergence of influenza viral variants. During the study period, influenza virus circulation was detected from January to December. Influenza A and B, and all current subtypes of human influenza viruses, were present each year. Throughout the 2010 post-pandemic season, influenza A(H1N1)pdm09, unexpectedly, almost disappeared. The haemagglutinin (HA) of the A(H1N1)pdm09 viruses studied were segregated in a different genetic group to those identified during the 2009 pandemic, although they were still antigenically closely related to the vaccine strain A/California/07/2009. Influenza A(H3N2) viruses were the predominant strains circulating during the 2011 season, accounting for nearly 76 % of influenza viruses identified. That year, all HA sequences of the A(H3N2) viruses tested fell into the A/Victoria/208/2009 genetic clade, but remained antigenically related to A/Perth/16/2009 (reference vaccine recommended for this three-year period). A(H3N2) viruses isolated in 2012 were antigenically closely related to A/Victoria/361/2011, recommended by the WHO as the H3 component for the 2013 Southern Hemisphere formulation. B viruses belonging to the B/Victoria lineage circulated in 2010. A mixed circulation of viral variants of both B/Victoria and B/Yamagata lineages was detected in 2012, with the former being predominant. A(H1N1)pdm09 viruses remained antigenically closely related to the vaccine virus A/California/7/2009; A(H3N2) viruses continually evolved into new antigenic clusters and both B lineages, B/Victoria/2/87-like and B/Yamagata/16/88-like viruses, were observed during the study period. The virological surveillance showed that the majority of the circulating strains during the study period were antigenically related to the corresponding Southern Hemisphere vaccine strains except for the 2012 A(H3N2) viruses.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sara Jones ◽  
Shijulal Nelson-Sathi ◽  
Yejun Wang ◽  
Raji Prasad ◽  
Sabrina Rayen ◽  
...  

Abstract Influenza A (H1N1) continues to be a major public health threat due to possible emergence of a more virulent H1N1 strain resulting from dynamic changes in virus adaptability consequent to functional mutations and antigenic drift in the hemagglutinin (HA) and neuraminidase (NA) surface proteins. In this study, we describe the genetic and evolutionary characteristics of H1N1 strains that circulated in India over a period of nine years from 2009 to 2017 in relation to global strains. The finding is important from a global perspective since previous phylogenetic studies have suggested that the tropics contributed substantially to the global circulation of influenza viruses. Bayesian phylogenic analysis of HA sequences along with global strains indicated that there is a temporal pattern of H1N1 evolution and clustering of Indian isolates with globally circulating strains. Interestingly, we observed four new amino acid substitutions (S179N, I233T, S181T and I312V) in the HA sequence of H1N1 strains isolated during 2017 and two (S181T and I312V) were found to be unique in Indian isolates. Structurally these two unique mutations could lead to altered glycan specificity of the HA gene. Similarly, sequence and structural analysis of NA domain revealed that the presence of K432E mutation in H1N1 strains isolated after 2015 from India and in global strains found to induce a major loop shift in the vicinity of the catalytic site. The findings presented here offer an insight as to how these acquired mutations could be associated to an improved adaptability of the virus for efficient human transmissibility.


2009 ◽  
Vol 14 (32) ◽  
Author(s):  
H Uphoff ◽  
S Geis ◽  
A Grüber ◽  
A M Hauri

For the next influenza season (winter 2009-10) the relative contributions to virus circulation and influenza-associated morbidity of the seasonal influenza viruses A(H3N2), A(H1N1) and B, and the new influenza A(H1N1)v are still unknown. We estimated the chances of seasonal influenza to circulate during the upcoming season using data of the German influenza sentinel scheme from 1992 to 2009. We calculated type and subtype-specific indices for past exposure and the corresponding morbidity indices for each season. For the upcoming season 2009-10 our model suggests that it is unlikely that influenza A(H3N2) will circulate with more than a low intensity, seasonal A(H1N1) with more than a low to moderate intensity, and influenza B with more than a low to median intensity. The probability of a competitive circulation of seasonal influenza A with the new A(H1N1)v is low, increasing the chance for the latter to dominate the next influenza season in Germany.


2014 ◽  
Vol 19 (1) ◽  
Author(s):  
E Takashita ◽  
M Ejima ◽  
R Itoh ◽  
M Miura ◽  
A Ohnishi ◽  
...  

Six influenza A(H1N1)pdm09 viruses were detected in Sapporo, Japan, between November and December 2013. All six viruses possessed an H275Y substitution in the neuraminidase protein, which confers cross-resistance to oseltamivir and peramivir. No epidemiological link among the six cases could be identified; none of them had received neuraminidase inhibitors before specimen collection. The haemagglutinin and neuraminidase genes of the six viruses were closely related to one another, suggesting clonal spread of a single resistant virus.


2016 ◽  
Vol 21 (13) ◽  
Author(s):  
Eeva Broberg ◽  
Angeliki Melidou ◽  
Katarina Prosenc ◽  
Karoline Bragstad ◽  
Olav Hungnes ◽  
...  

Influenza A(H1N1)pdm09 viruses predominated in the European influenza 2015/16 season. Most analysed viruses clustered in a new genetic subclade 6B.1, antigenically similar to the northern hemisphere vaccine component A/California/7/2009. The predominant influenza B lineage was Victoria compared with Yamagata in the previous season. It remains to be evaluated at the end of the season if these changes affected the effectiveness of the vaccine for the 2015/16 season.


2012 ◽  
Vol 82 (3) ◽  
pp. 187-193 ◽  
Author(s):  
M. Jonges ◽  
J. Rahamat-Langendoen ◽  
A. Meijer ◽  
H.G. Niesters ◽  
M. Koopmans

Author(s):  
Merryn Roe ◽  
Matthew Kaye ◽  
Pina Iannello ◽  
Hilda Lau ◽  
Iwona Buettner ◽  
...  

As part of its role in the World Health Organization’s (WHO) Global Influenza Surveillance and Response System (GISRS), the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne received a record total of 5866 human influenza positive samples during 2017. Viruses were analysed for their antigenic, genetic and antiviral susceptibility properties and were propagated in qualified cells and hens’ eggs for use as potential seasonal influenza vaccine virus candidates. In 2017, influenza A(H3) viruses predominated over influenza A(H1)pdm09 and B viruses, accounting for a total of 54% of all viruses analysed. The majority of A(H1)pdm09, A(H3) and influenza B viruses analysed at the Centre were found to be antigenically similar to the respective WHO recommended vaccine strains for the Southern Hemisphere in 2017. However, phylogenetic analysis indicated that the majority of circulating A(H3) viruses had undergone genetic drift relative to the WHO recommended vaccine strain for 2017. Of 3733 samples tested for susceptibility to the neuraminidase inhibitors oseltamivir and zanamivir, only two A(H1)pdm09 viruses and one A(H3) virus showed highly reduced inhibition by oseltamivir, while just one A(H1)pdm09 virus showed highly reduced inhibition by zanamivir.


2012 ◽  
Vol 17 (9) ◽  
Author(s):  
J Beauté ◽  
E Broberg ◽  
F Plata ◽  
I Bonmarin ◽  
J O’Donnell ◽  
...  

In France, Ireland, Spain and the United Kingdom, the influenza season 2011/12 started in the final weeks of 2011 and has been dominated by influenza A(H3) viruses with minimal circulation of influenza A(H1N1)pdm09 and B viruses. A relatively greater proportion, however, of influenza A(H1N1)pdm09 viruses were reported in hospitalised laboratory-confirmed influenza cases in four countries. Compared to the season 2010/11, the proportion of subtype A(H3) among hospitalised cases has increased, associated with a larger proportion of cases in the youngest and oldest age groups.


2014 ◽  
Vol 61 (3) ◽  
Author(s):  
Aneta Nitsch-Osuch ◽  
Lidia Bernadeta Brydak

Neuraminidase inhibitors (NAIs) are antiviral drugs for treatment and prophylaxis of influenza. By blocking the activity of the enzyme neuraminidase, NAIs prevent new viral particles from being released. The increasing use of NAIs brings into focus the risk of drug resistance arising to the class. There are three levels of antiviral resistance according to the way that resistance can be detected or inferred: genotypic, phenotypic and clinical resistance. For many years seasonal influenza viruses resistance to NAIs was low (0.33%). Recently, there has been described an increasing number of resistant seasonal influenza strains to oseltamivir (2% in adults, 5-18% in children). In 2007 there were published data describing 14% resistant to oseltamivir strains of influenza A/H1N1/ in Europe. Approximately 0.5-1.0% of influenza A/H1N1/pdm09 isolates are currently resistant to oseltamivir. The established markers of the resistance to oseltamivir were found in 2.4% of human and 0.8% of avian isolates of influenza A/H5N1/. It has been not observed a cross resistance among oseltamivir and zanamivir. NAIs resistance in influenza viruses is relative and despite its presence patients with resistant viruses may still benefit from receiving these antivirals. The response to treatment with antivirals remains the most important proof of antiviral effectiveness. The rational use of NAIs is essential to preserve the best choice for treatment and prophylaxis of seasonal, avian and pandemic influenza.


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