Skip to main content

Intensive #reassortment and frequent #intercontinental #transmission revealed by long-term genetic analysis of #H10 avian #influenza viruses in #Taiwan

Image
By G.M.

 


ABSTRACT

H10 subtype avian influenza viruses primarily circulate among wild waterfowl but can occasionally infect mammals, including humans, and recent sporadic human cases have raised significant public health concerns. In this study, we sequenced and analysed 59 H10 subtype viruses isolated from wild birds in Taiwan. Results showed that all isolates were genetically distinct from human and other mammalian H10 subtype isolates. Taiwanese isolates exhibited high genetic diversity and could be categorized into 34 distinct genotypes, with each genotype circulating only in a single migratory season and not recurring during subsequent seasons. Additional analyses revealed that certain gene pools frequently circulate in the Pacific Rim, with evidence of North American lineage genes establishing long-term populations in Eurasia and vice versa. Although no characteristics indicative of mammalian adaptation was found in the Taiwanese isolates, temporal changes in the haemagglutinin cleavage site sequences were observed. This study provides a comprehensive overview of the evolutionary dynamics of H10 avian influenza viruses isolated from wild birds in Taiwan, emphasizing the complexity of intercontinental gene flow and viral reassortment. Currently, no consistent molecular markers indicating the impact of H10 avian influenza viruses on mammals or poultry have been identified. Notably, the observed changes in the haemagglutinin cleavage site sequences among Eurasian viruses suggest potential antigenic variations, indicating a need for further investigation into these changes. This potential highlights the necessity of ongoing surveillance to track the evolution and transmission dynamics of these viruses.

Source: Emerging Microbes and Infections, https://www.tandfonline.com/doi/full/10.1080/22221751.2025.2556794#abstract

____

Labels:

Comments

Post a Comment

Popular posts from this blog

#Neuroinvasive #Oropouche virus in a patient with #HIV from extra-Amazonian #Brazil

By G.M.
{Excerpt} A novel reassortant Oropouche virus (OROV) lineage (with medium [M], large [L], and small [S] RNA segments : M1L2S2) has driven Brazil's largest and most geographically widespread OROV epidemic , expanding beyond the endemic Amazon basin to establish local transmission across multiple Brazilian states and other previously unaffected Latin American countries . The rapid spread of this lineage underscores its evolutionary potential and reinforces its significance as a public health threat .1 Similar to chikungunya and Zika viruses, expanding arboviruses can exhibit unexpected clinical and epidemiological shifts , including vertical transmissions , neuroinvasive effects, and potentially fatal outcomes.2–4 Although OROV typically causes self-limited febrile illness, accumulating clinical and experimental evidence suggests neurotropic potential .5 This Correspondence describes the first confirmed case of neuroinvasive OROV infection caused by the emergent M1L2S2 lineage in ext...
Post a Comment
Read more »

No evidence of immune #exhaustion after repeated #SARS-CoV-2 #vaccination in vulnerable and healthy populations

By G.M.
Abstract Frequent SARS-CoV-2 vaccination in vulnerable populations has raised concerns that this may contribute to T cell exhaustion , which could negatively affect the quality of immune protection. Herein, we examined the impact of repeated SARS-CoV-2 vaccination on T cell phenotypic and functional exhaustion in frail older adults in long-term care (n = 23), individuals on immunosuppressive drugs (n = 10), and healthy adults (n = 43), in Canada . Spike-specific CD4+ and CD8+ T cell levels did not decline in any cohort following repeated SARS-CoV-2 vaccination, nor did the expression of exhaustion markers on spike-specific or total T cells increase. T cell production of multiple cytokines (i.e. polyfunctionality) in response to the spike protein of SARS-CoV-2 did not decline in any cohort following repeated vaccination. None of the cohorts displayed elevated levels of terminally differentiated T cells following multiple SARS-CoV-2 vaccinations. Thus, repeated SARS-CoV-2 vaccination was...
Post a Comment
Read more »

Chimeric #hemagglutinin and #M2 #mRNA #vaccine for broad #influenza subtype protection

By G.M.
Abstract Since multiple and unpredicted influenza viruses cause seasonal epidemics and even high-risk pandemics , developing a universal influenza vaccine is essential to provide broad protection against various influenza subtypes. Combined with the mRNA lipid nanoparticle-encapsulated (mRNA-LNP) vaccine platform and chimeric immunogen strategy , we developed a novel cocktail mRNA vaccine encoding chimeric HAs (cH5/1-BV, cH7/3) and intact M2 (termed Fluaxe), which confers broad protection against major circulating IAVs and IBVs , as well as highly pathogenic avian influenza . Two-dose intramuscular immunization of Fluaxe in mice elicited cross-reactive neutralizing antibodies , T cell responses, and long-lived immunity, resulting in robust protection against multiple lethal influenza virus infections and severe acute lung injuries . In particular, intramuscular administration stimulated systemic immunity together with a prominent lung tropism of memory cells . Moreover, Fluaxe immuniza...
Post a Comment
Read more »