Skip to main content

#Genomic #signatures and #host #adaptation of #H5N1 clade 2.3.4.4b: A call for global #surveillance and multi-target antiviral strategies

Image
By G.M.

Highlights

• Phylogenetic analysis of genotype B3.13 and D1.1 across the species.

• Mutations on the receptor binding sites related to receptor preferring.

• Host adaptability differences between B3.13 and D1.1.

• Antivirals resistance mutations emergence of genotype B3.13 and D1.1.


Abstract

The recent report of the first fatality associated with infection by influenza virus H5N1 clade 2.3.4.4b, identified as genotype D1.1, which is distinct from the B3.13 genotype, has sparked fears of a potential human pandemic. However, the genetic relationships between B3.13 and D1.1, as well as their origins, host adaptability, and antiviral resistance, remain poorly understood. Here we conducted a comprehensive phylogenetic and comparative analysis of H5N1 clade 2.3.4.4b across multiple species, in order to identify the molecular characteristics and frequency of resistance mutations in these two genotypes, elucidate their evolutionary trajectories, and assess their implications for public health. Our results demonstrate that B3.13 exhibits mammalian adaptability, while D1.1 retains avian adaptability. Importantly, both genotypes display limited occurrences of human-like signatures, which can help alleviate public anxiety. Additionally, the emergence of the resistance mutations in the clade 2.3.4.4b on the binding sites of antivirals calls for the development of multi-target antiviral strategies to mitigate the risk of resistant strain reassortment.

Source: Current Research in Microbiological Sciences, https://www.sciencedirect.com/science/article/pii/S2666517425000392?via%3Dihub

____

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 »