Phylogenetic analysis of human influenza A/H3N2 viruses isolated in 2015 in Germany indicates significant genetic divergence from vaccine strains

Mostafa, Ahmed; Mostafa, Ahmed; Slanina, Heiko; Hussein, Mohamed A.; Kuznetsova, Irina; Schüttler, Christian G.; Ziebuhr, John; Pleschka, Stephan

doi:10.1007/s00705-016-2815-x

Cited by 17 publications

(20 citation statements)

References 25 publications

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“…Glycosylation and deglycosylation are essential viral mechanisms to accommodate in the host organisms . There was no distinct glycosylation pattern observed across influenza seasons in Northern Cameroon.…”

Section: Discussionmentioning

confidence: 91%

Genetic diversity of influenza A(H3N2) viruses in Northern Cameroon during the 2014‐2016 influenza seasons

Njifon

Monamele

Vernet

et al. 2019

Journal of Medical Virology

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In Cameroon, genome characterization of influenza virus has been performed only in the Southern regions meanwhile genetic diversity of this virus varies with respect to locality. The Northern region characterized by a Sudan tropical climate might have distinct genetic characterization. This study aimed to better understand the genetic diversity of influenza A(H3N2) viruses circulating in Northern Cameroon. Sequences of three gene segments (hemagglutinin (HA), neuraminidase (NA) and matrix (M) genes) were obtained from 16 A(H3N2) virus strains collected during the 2014 to 2016 influenza seasons in Garoua. The HA gene segments were analysed with respect to reference strains while the NA and M gene was analysed for reported genetic markers of resistance to antivirals. Analysis of the HA sequences revealed that majority of the virus strains grouped together with the 2016‐2017 vaccine strain (3C.2a‐A/Hong Kong/4801/2014) while 3/5 (60%) of the 2015 viral strains grouped together with the 2015‐2016 vaccine strain 3C.3a‐A/Switzerland/9715293/2013. Within clade 3C.2a, Northern Cameroon sequences mostly grouped in sub‐clade A3 (10/16). Analysis of the coding regions of the NA and M genes showed that none had genetic markers of resistance to neuraminidase inhibitors but all strains possessed the S31N substitution of resistance to amantadine. Due to some discrepancies observed in this region with respect to the Southern regions of Cameroon, there is necessity of including all regions within a country in the sentinel surveillance of influenza. These data will enable to track changes in influenza viruses in Cameroon.

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Section: Discussionmentioning

confidence: 91%

Genetic diversity of influenza A(H3N2) viruses in Northern Cameroon during the 2014‐2016 influenza seasons

Njifon

Monamele

Vernet

et al. 2019

Journal of Medical Virology

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“…All analyzed Kenyan A (H1N1) pdm09 subclade 6B.1 members displayed an additional N-glycosylation at residue sites 162-164 attributed to the S162N substitution [42]. The potential gain or loss of N-linked glycosylation at HA1 epitope sites can alter influenza virus antigenic properties [13,49].…”

Section: Discussionmentioning

confidence: 99%

Assessing antigenic drift and phylogeny of influenza A (H1N1) pdm09 virus in Kenya using HA1 sub-unit of the hemagglutinin gene

et al. 2020

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Influenza A (H1N1) pdm09 virus emerged in North America in 2009 and has been established as a seasonal strain in humans. After an antigenic stasis of about six years, new antigenically distinct variants of the virus emerged globally in 2016 necessitating a change in the vaccine formulation for the first time in 2017. Herein, we analyzed thirty-eight HA sequences of influenza A (H1N1) pdm09 strains isolated in Kenya during 2015-2018 seasons, to evaluate their antigenic and molecular properties based on the HA1 sub-unit. Our analyses revealed that the A (H1N1) pdm09 strains that circulated in Kenya during this period belonged to genetic clade 6B, subclade 6B.1 and 6B.2. The Kenyan 2015 and 2016 isolates differed from the vaccine strain A/California/07/2009 at nine and fourteen antigenic sites in the HA1 respectively. Further, those isolated in 2017 and 2018 correspondingly varied from A/Michigan/45/2015 vaccine strain at three and fifteen antigenic sites. The predicted vaccine efficacy of A/California/07/2009 against Kenyan 2015/2016 was estimated to be 32.4% while A/Michigan/45/2015 showed estimated vaccine efficacies of 39.6% -41.8% and 32.4% -42.1% against Kenyan 2017 and 2018 strains, respectively. Hemagglutinationinhibition (HAI) assay using ferret post-infection reference antiserum showed that the titers for the Kenyan 2015/2016 isolates were 2-8-fold lower compared to the vaccine strain. Overall, our results suggest the A (H1N1) pdm09 viruses that circulated in Kenya during 2015/2016 influenza seasons were antigenic variants of the recommended vaccine strains, denoting sub-optimal vaccine efficacy. Additionally, data generated point to a swiftly evolving influenza A (H1N1) pdm09 virus in recent post pandemic era, underscoring the need for sustained surveillance coupled with molecular and antigenic analyses, to inform appropriate and timely influenza vaccine update.

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“…These findings are consistent with previous studies, which reported the overall ω values for the NA genes of 0.30 for seasonal A(H1N1), 0.32 for A(H1N1)pdm09, 0.29 for A(H3N2), and 0.20–0.31 for influenza B virus [3, 51, 54, 57]. The selection pressure of NA of A(H3N2) in German was 0.21, while in Taiwan it was 0.37 [58–59]. Moreover, the findings showed that NA gene had highest a number of amino acid residue under the positive selection.…”

Section: Discussionmentioning

confidence: 99%

Evolution of the neuraminidase gene of seasonal influenza A and B viruses in Thailand between 2010 and 2015

et al. 2017

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The neuraminidase inhibitors (NAIs) oseltamivir and zanamivir are commonly used for the treatment and control of influenza A and B virus infection. However, the emergence of new influenza virus strains with reduced susceptibility to NAIs may appear with the use of these antivirals or even naturally. We therefore screened the neuraminidase (NA) sequences of seasonal influenza virus A(H1N1), A(H1N1)pdm09, A(H3N2), and influenza B virus strains identified in Thailand for the presence of substitutions previously reported to reduce susceptibility to NAIs. We initially examined oseltamivir resistance (characterized by the H275Y mutation in the NA gene) in 485 A(H1N1)pdm09 strains circulating in Thailand and found that 0.82% (4/485) had this substitution. To further evaluate the evolution of the NA gene, we also randomly selected 98 A(H1N1)pdm09, 158 A(H3N2), and 69 influenza B virus strains for NA gene amplification and sequencing, which revealed various amino acid mutations in the active site of the NA protein previously shown to be associated with reduced susceptibility to NAIs. Phylogenetic analysis of the influenza virus strains from this study and elsewhere around the world, together with the estimations of nucleotide substitution rates and selection pressure, and the predictions of B-cell epitopes and N-linked glycosylation sites all provided evidence for the ongoing evolution of NA. The overall rates of NA evolution for influenza A viruses were higher than for influenza B virus at the nucleotide level, although influenza B virus possessed more genealogical diversity than that of influenza A viruses. The continual surveillance of the antigenic changes associated with the NA protein will not only contribute to the influenza virus database but may also provide a better understanding of selection pressure exerted by antiviral use.

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Phylogenetic analysis of human influenza A/H3N2 viruses isolated in 2015 in Germany indicates significant genetic divergence from vaccine strains

Cited by 17 publications

References 25 publications

Genetic diversity of influenza A(H3N2) viruses in Northern Cameroon during the 2014‐2016 influenza seasons

Genetic diversity of influenza A(H3N2) viruses in Northern Cameroon during the 2014‐2016 influenza seasons

Assessing antigenic drift and phylogeny of influenza A (H1N1) pdm09 virus in Kenya using HA1 sub-unit of the hemagglutinin gene

Evolution of the neuraminidase gene of seasonal influenza A and B viruses in Thailand between 2010 and 2015

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