#Molecular characterisation of novel #reassortants of the G57 #genotype of low-pathogenic avian #influenza #H9N2 virus isolated from #poultry #farms in #Malaysia

Source: Archives of Virology, https://link.springer.com/article/10.1007/s00705-024-06159-4

Abstract
In late 2017, Malaysia reported repeated outbreaks of low-pathogenic avian influenza virus (LPAI) H9N2 infections in commercial poultry flocks. Two H9N2 viruses, A/chicken/Malaysia/Negeri Sembilan/UPM994/2018 and A/chicken/Malaysia/Johore/UPM2033/2019, which were isolated from breeder and layer flocks in Peninsular Malaysia, were characterised in this study. Phylogenetic analysis revealed that both viruses were multiple-genotype reassortant strains with genes originating from Y280-like (HA gene), F/98-like (NS, NP and PA), G1-like (M and PB2), and Korean-like (PB1) lineages, indicating that they belong to a novel genotype that is divergent from the G57 lineage of Chinese origin. Both isolates were predicted to have a dibasic cleavage site (333-PSRSSRGLF-341) in the HA gene cleavage locations. Thus, the novel Malaysian H9N2 strain is a Y280-like virus resembling H9N2 isolates from Indonesia, Taiwan, Japan, and Cambodia. This virus is of the G57 lineage but has a novel genotype of the PB1 gene originating from a Korean-lineage H9N2 virus, which has not been detected before in the region.

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#aH9n2 #abstract #avianInfluenza #genetics #health #influenza #malaysia #news #poultry #REASSORTANTSTRAIN #research #science

Analyzing #Molecular #Traits of #H9N2 Avian #Influenza Virus Isolated from a Same #Poultry #Farm in West #Java Province, #Indonesia, in 2017 and 2023

Source: F1000 Research, https://f1000research.com/articles/13-571/v2

Abstract
Background
Indonesia is one of the countries that is endemic to avian influenza virus subtype H9N2. This study aims to compare the molecular characteristics of avian influenza virus (AIV) subtype H9N2 from West Java.

Methods
Specific pathogen-free (SPF) embryonated chicken eggs were used to inoculate samples. RNA extraction and RT–qPCR confirmed the presence of H9 and N2 genes in the samples. RT–PCR was employed to amplify the H9N2-positive sample. Nucleotide sequences were obtained through Sanger sequencing and analyzed using MEGA 7. Homology comparison and phylogenetic tree analysis, utilizing the neighbor-joining tree method, assessed the recent isolate’s similarity to reference isolates from GenBank. Molecular docking analysis was performed on the HA1 protein of the recent isolate and the A/Layer/Indonesia/WestJava-04/2017 isolate, comparing their interactions with the sialic acids Neu5Ac2-3Gal and Neu5Ac2-6Gal.

Results
RT–qPCR confirmed the isolate samples as AIV subtype H9N2. The recent virus exhibited 11 amino acid residue differences compared to the A/Layer/Indonesia/WestJava-04/2017 isolate. Phylogenetically, the recent virus remains within the h9.4.2.5 subclade. Notably, at antigenic site II, the recent isolate featured an amino acid N at position 183, unlike A/Layer/Indonesia/WestJava-04/2017. Molecular docking analysis revealed a preference of HA1 from the 2017 virus for Neu5Ac2-3Gal, while the 2023 virus displayed a tendency to predominantly bind with Neu5Ac2-6Gal.

Conclusion
In summary, the recent isolate displayed multiple mutations and a strong affinity for Neu5Ac2-6Gal, commonly found in mammals.

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#aH9n2 #abstract #avianInfluenza #AVIANINFLUENZA #birdFlu #health #indonesia #news #poultry #research

13th #Meeting of #WHO Expert Working #Group on #Surveillance of #Antiviral Susceptibility of #Influenza Viruses for WHO #GISRS

Source: World Health Organization, Weekly Epidemiological Record: https://www.who.int/publications/journals/weekly-epidemiological-record

{Excerpt, edited}

Executive summary

The WHO Expert Working Group on Surveillance of Influenza Antiviral Susceptibility (AVWG) supports the WHO Global Influenza Surveillance and Response System (GISRS) by providing practical guidance for monitoring the antiviral susceptibility of seasonal and emerging influenza viruses The 13th WHO AVWG meeting was held in hybrid format (faceto-face and virtually) on 13–14 June 2024 in Lyon, France.

Update on susceptibility of seasonal influenza viruses to approved antiviral agents

Between May 2023 and May 2024, WHO collaborating centres (CCs) and participating national influenza centres (NICs) reported that seasonal influenza activity in various regions had resumed to levels before the coronavirus disease 2019 (COVID-19) pandemic. Co-circulation of A(H1N1)pdm09, A(H3N2) and influenza B/Victoria lineage viruses was detected in most regions. Overall, influenza A and B viruses with reduced inhibition (RI) or highly reduced inhibition (HRI) to neuraminidase (NA) inhibitors (NAIs) were detected at low frequency. The most frequently identified substitution associated with RI or HRI by NAIs was NA-H275Y in A(H1N1)pdm09 viruses, which was detected at <2%. Double amino acid substitutions (NA-I223V+ NA-S247N) in A(H1N1)pdm09 viruses (referred to as dual mutant viruses) that resulted in RI by oseltamivir were first detected in May 2023 and spread rapidly to several regions of the world.{1,2} Influenza A and B viruses with amino acid substitutions in the polymerase acidic (PA) protein associated with reduced susceptibility to endonuclease inhibitor (baloxavir) were detected at low frequency. The PA-I38X (including I38T, I38N, I38M and I38V) amino acid substitution being the most frequently reported, but the overall detection frequency has remained low (<2%).

Update on susceptibility of zoonotic and animal influenza viruses to approved antiviral agents

From May 2023 to May 2024, clade 2.3.4.4b A(H5N1) highly pathogenic avian influenza (HPAI) viruses continued to be detected in various regions of the world. Since early 2024, there has been an outbreak of clade 2.3.4.4b A(H5N1) genotype B3.13 viruses in dairy cattle in several states in the United States of America, resulting in sporadic zoonotic infections in humans. In addition, human infection with clade 2.3.2.1c A(H5N1) HPAI has been reported in Cambodia and Viet Nam. WHO CCs, participating NICs and WHO H5 reference laboratories reported antiviral susceptibility testing of A(H5N1) HPAI, low pathogenic avian influenza (LPAI) of various subtypes and swine influenza viruses. Of the clade 2.3.4.4b A(H5N1) HPAI viruses, the NA-T438I substitution, which confers RI by zanamivir and peramivir, was detected at <2% frequency. NA-H275Y, NA-N295S and NA-N295S+NA-T438N associated with RI or HRI by NAIs were also detected among A(H5N1) viruses. NA-T438I has been detected in A(H5N1) viruses isolated from dairy cattle. PA-I38T, PA-A37T and PA-I38M, associated with reduced susceptibility to baloxavir, were detected in A(H5N1) viruses. Most A(H5N1) HPAI viruses remain susceptible to M2 ion channel blockers. Among LPAI, NA-H274Y with HRI by oseltamivir was detected in one A(H8N4) isolate. PA-E199G with reduced susceptibility to baloxavir was detected in one A(H9N2) virus. Overall, animal or zoonotic influenza viruses with reduced susceptibility to NAIs or baloxavir were detected at very low frequencies.

Update of protocols and guidance for GISRS laboratories

Genotypic and/or phenotypic assays can be used to monitor the susceptibility of influenza viruses to NAIs and baloxavir. The WHO AVWG routinely reviews and updates information on NA{3,4} and PA{5} amino acid substitutions associated with reduced susceptibility to NAIs and baloxavir, respectively. Reference virus panels that can be used for NAI and baloxavir susceptibility testing are available for GISRS laboratories at the International Reagent Resource.{6} The WHO AVWG will develop an algorithm for NICs to decide on testing strategies (genotypic versus phenotypic) and methods according to their capacity. Guidance on phenotypic assays for NAI susceptibility testing is provided in a WHO guidance document to NICs, which was updated in 2018.{7} A new phenotypic assay has been developed for testing susceptibility to baloxavir.{8} The protocol will be posted on the WHO website. The WHO-AVWG will also update the WHO guidance document to NICs to include the new phenotypic assay for baloxavir susceptibility testing. In addition, the WHO AVWG will work with the Global Initiative on Sharing All Influenza Data{9} to facilitate identification of NA and PA substitutions in submitted sequences.

Review of external quality assessment programme (EQAP) panels

EQAP was initiated in 2007, and the antiviral panel was introduced in 2013 (panel 12) as an optional component of EQAP to evaluate the ability of NICs to identify influenza viruses with reduced susceptibility to NAIs. Genotypic testing for baloxavir susceptibility was introduced in 2020 (panel 19) for educational purpose (i.e. not scored). Results for the 2023 Global EQAP panel were reported at the 13th WHO AVWG meeting. A total of 178 laboratories participated in the 2023 EQAP; 46 (25.8%) participated in NAI susceptibility testing and 16 (9.0%) in baloxavir susceptibility testing. The results from the Global EQAP antiviral panel are used by members of the WHO AVWG to assess the training requirements of NICs.

Way forward

Two reports, on global antiviral surveillance in 2020-2023 and in 2023–2024, are being prepared for publication. The next WHO AVWG meeting is scheduled for June 2025.

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{1} Leung RC et al. Global emergence of neuraminidase inhibitor-resistant influenza A(H1N1)pdm09 viruses with I223V and S247N mutations: implications for antiviral resistance monitoring. Lancet Microbe. 2024;5(7):627–8. doi:10.1016/S26665247(24)00037-5.

{2} Patel MC et al. Multicountry spread of influenza A(H1N1)pdm09 viruses with reduced oseltamivir inhibition, May 2023-February 2024. Emerg Infect Dis. 2024;30(7):1410–5. doi:10.3201/eid3007.240480.

{3} Summary of neuraminidase (NA) amino acid substitutions associated with reduced inhibition by neuraminidase inhibitors (NAIs). Geneva: World Health Organization; 2023 (https://www.who.int/publications/m/item/summary-of-neuraminidase-(na)-amino-acid-substitutions-associated-with-reduced-inhibition-by-neuraminidase-inhibitors-(nais).

{4} Summary of neuraminidase (NA) amino acid substitutions associated with reduced inhibition by neuraminidase inhibitors (NAIs) among avian influenza viruses of Group 1 and Group 2 NAs. Geneva: World Health Organization; 2024 (https://www. who.int/publications/m/item/summary-of-neuraminidase-(na)-amino-acid-substitutions-associated-with-reduced-inhibition-by-neuraminidase-inhibitors-(nais)among-avian-influenza-viruses-of-group-1-and-group-2-nas).

{5} Summary of polymerase acidic (PA) protein amino acid substitutions analysed for their effects on baloxavir susceptibility. Geneva: World Health Organization; 2024 (https://www.who.int/publications/m/item/summary-of-polymerase-acidic-(pa)-protein-amino-acid-substitutions-analysed-for-their-effects-on-baloxavirsusceptibility).

{6} See https://www.internationalreagentresource.org.

{7} Practical guidance for national influenza centres establishing or implementing neuraminidase inhibitor susceptibility surveillance. Geneva: World Health Organization; 2024 (https://www.who.int/publications/i/item/practical-guidance-for-national-inf luenza-centres-establishing-or-implementing-neuraminidase-inhibitor-susceptibility-surveillance).

{8} Baloxavir susceptibility assessment using influenza replication inhibition neuraminidase-based assay (IRINA). Atlanta (GA): Centers for Disease Control and Prevention; 2023 (https://cdn.who.int/media/docs/default-source/influenza/avwg/ cdc-phenotypic-lp-492rev01d—baloxavir-susceptibility-assessment-using-irina. pdf?sfvrsn=f24254ac_3).

{9} See https://gisaid.org.

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#aH3n2 #aH5n1 #aH9n2 #amantadine #antivirals #AVIANINFLUENZA #baloxavir #birdFlu #drugsResistance #h1n1pdm09 #h5n1 #health #influenza #oseltamivir #science #SEASONALINFLUENZA #updates #WHO #zanamivir

Sustained #vaccine #exposure elicits more rapid, consistent, and broad #humoral immune responses to multivalent #influenza #vaccines

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2024.04.28.591370v2

Abstract
With the ever-present threat of pandemics, it is imperative we develop vaccine technologies eliciting broad and durable immunity to high-risk pathogens. Yet, current annual influenza vaccines, for example, fail to provide robust immunity against the 3-4 homologous strains they contain, let alone heterologous strains. Herein, we demonstrate that sustained delivery of multivalent influenza vaccines from an injectable polymer-nanoparticle (PNP) hydrogel technology induces more rapid, consistent, and potent humoral immune responses against multiple homologous viruses, as well as potent responses against heterologous viruses and potential pandemic subtypes H5N1, H7N9 and H9N2. Further, admixing PNP hydrogels with commercial influenza vaccines results in stronger hemagglutination inhibition against both heterologous and homologous viruses. We show this enhanced potency and breadth arises from higher affinity antibodies targeting both the hemagglutinin stem and head. Overall, this simple and effective sustained delivery platform for multivalent annual influenza vaccines generates durable, potent, and remarkably broad immunity to influenza.

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#aH5n1 #aH7n9 #aH9n2 #abstract #avianInfluenza #COVID19 #health #influenza #influenzaA #news #research #vaccine #vaccines

Source: Centre for Health Protection, Hong Kong PRC SAR, https://www.chp.gov.hk/files/pdf/2024_avian_influenza_report_vol20_wk45.pdf

{Excerpts, edited}

On November 12 2024, the Ministry of Health of China notified to HK PRC SAR seven additional cases of human infection with H9N2 avian influenza virus, as follow:

1. Hubei Province, A six-year-old boy with onset on October 7, 2024.
2. Hunan Province, A ten-month-old boy with onset on September 30, 2024.
3. Hunan Province, A one-year-old girl with onset on October 8, 2024.
4. Hunan Province, A three-year-old boy with onset on October 11, 2024.
5. Hunan Province, A five-year-old boy with onset on October 14, 2024.
6. Jiangxi Province, A seven-year-old boy with onset on October 8, 2024.
7. Sichuan Province, A 67-year-old woman with onset on September 23, 2024.

(…)

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https://etidioh.wordpress.com/2024/11/12/china-reported-seven-new-human-cases-of-infection-with-avian-influenza-h9n2-virus-as-of-nov-12-24/

#aH9n2 #AVIANINFLUENZA #china #HKPRCSAR #hubei #human #hunan #jiangxi #sichuan #updates

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2024.11.04.621830v1

Abstract
Airborne transmission is an essential mode of infection and spread of influenza viruses among humans. However, most studies use liquid inoculum for virus infection. To better replicate natural airborne infections in vitro, we generated a calm-aerosol settling chamber system designed to examine the aerosol infectivity of influenza viruses in different cell types. Aerosol inoculation was characterized for multiple influenza A virus (FLUAV) subtypes, including a pandemic 2009 H1N1, a seasonal swine H3N2, and an avian H9N2 using this exposure system. While each FLUAV strain displayed high infectivity within MDCK cells via liquid inoculation, differences in infectivity were observed during airborne inoculation. This was further observed in recently developed immortalized differentiated human airway epithelial cells (BCi-NS1.1) cultured in an air-liquid interface. The airborne infectious dose 50 for each virus was based on the exposure dose per well. Our findings indicate that this system has the potential to enhance our understanding of the factors influencing influenza transmission via the airborne route. This could be invaluable for conducting risk assessments, potentially reducing the reliance on extensive and costly in vivo animal studies.

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https://etidioh.wordpress.com/2024/11/06/air-liquid-interface-model-for-influenza-aerosol-exposure-in-vitro/

#aH3n2 #aH9n2 #abstract #avianFlu #birdFlu #h1n1pdm09 #health #influenza #influenzaA #news #pathogensAirborneTransmission #research

Source: Journal of Virology, https://journals.asm.org/doi/10.1128/jvi.00928-24

ABSTRACT
A better understanding of viral factors that contribute to influenza A virus (IAV) airborne transmission is crucial for pandemic preparedness. A limited capacity for airborne transmission was recently observed in a human A(H9N2) virus isolate (A/Anhui-Lujiang/39/2018, AL/39) that possesses a leucine (L) residue at position HA1-226 (H3 numbering), indicative of human-like receptor binding potential. To evaluate the roles of the residue at this position in virus fitness and airborne transmission, a wild-type AL/39 (AL/39-wt) and a mutant virus (AL/39-HA1-L226Q) with a single substitution at position HA1-226 from leucine to glutamine (Q), a consensus residue in avian influenza viruses, were rescued and assessed in the ferret model. The AL/39-HA1-L226Q virus lost the ability to transmit by air, although the virus had a comparable capacity for replication, induced similar levels of host innate immune responses, and was detected at comparable levels in the air surrounding the inoculated ferrets relative to AL/39-wt virus. However, ferrets showed a lower susceptibility to AL/39-HA1-L226Q virus infection compared to the AL/39-wt virus. Furthermore, the AL/39-wt and AL/39-HA1-L226Q viruses each gained dominance in different anatomic sites in the respiratory tract in a co-infection competition model in ferrets. Taken together, our findings demonstrate that the increasing dominance of HA1-L226 residue in an avian A(H9N2) virus plays multifaceted roles in virus infection and transmission in the ferret model, including improved virus fitness and infectivity.

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https://etidioh.wordpress.com/2024/11/04/dissecting-the-role-of-the-ha1-226-leucine-residue-in-the-fitness-and-airborne-transmission-of-an-ah9n2-avian-influenza-virus/

#aH9n2 #abstract #animalModels #avianInfluenza #AVIANINFLUENZA #birdFlu #ferrets #h5n1 #health #news #research

Source: Lancet Microbe, https://www.thelancet.com/journals/lanmic/article/PIIS2666-5247(24)00234-9/fulltext

Summary
A systematic risk assessment approach is essential for evaluating the relative risk of influenza A viruses (IAVs) with pandemic potential. To achieve this, the Tool for Influenza Pandemic Risk Assessment (TIPRA) was developed under the Global Influenza Programme of WHO. Since its release in 2016 and update in 2020, TIPRA has been used to assess the pandemic risk of 11 zoonotic IAVs across ten evaluation rounds. Notably, A(H7N9), A(H9N2), and A(H5) clade 2.3.4.4 viruses were re-evaluated owing to changes in epidemiological characteristics or virus properties. A(H7N9) viruses had the highest relative risk at the time of assessment, highlighting the importance of continuous monitoring and reassessment as changes in epidemiological trends within animal and human populations can alter risk profiles. The knowledge gaps identified throughout the ten risk assessments should help to guide the efficient use of resources for future research, including surveillance. The TIPRA tool reflects the One Health approach and has proven crucial for closely monitoring virus dynamics in both human and non-human populations to enhance preparedness for potential IAV pandemics.

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https://etidioh.wordpress.com/2024/10/14/pandemic-risk-characterisation-of-zoonotic-influenza-a-viruses-using-the-tool-for-influenza-pandemic-risk-assessment-tipra/

#aH5n1 #aH7n9 #aH9n2 #abstract #avianInfluenza #pandemicInfluenza #pandemicPreparedness #research #TIPRA #WHO #zoonoses