ETIDIOH - NEW

  Abstract Most emerging human infectious diseases are derived from animals , and monitoring such zoonoses is imperative to help prevent future outbreaks . In this Forum , we discuss the knowledge gaps in our current understanding of viral ecology, global disparities in virus discovery , and the applications of artificial intelligence in infectious disease monitoring. Source: Cell Host & Microbe,  https://www.cell.com/cell-host-microbe/abstract/S1931-3128(25)00429-9?rss=yes ____

  Summary -- What is already known about this topic? - The H3N8 avian influenza virus (AIV) demonstrates considerable capacity for interspecies transmission and has been documented in multiple mammalian hosts , including equine and canine species. During 2022–2023, three laboratory-confirmed human infections with H3N8 were reported in China, heightening public health concerns about the zoonotic spillover potential of H3 subtype AIVs. -- What is added by this report? - This study reports the isolation of a genetically reassorted, low-pathogenicity H3N8 avian influenza virus (AIV) from an islet in Niukouyu Wetland Park, Beijing Municipality — the first detection of this viral strain in a wild environment within the city. Throat swabs collected from park staff tested negative for influenza viruses. Phylogenetic analysis demonstrated that the viral hemagglutinin gene originated from the Eurasian lineage, while the neuraminidase gene was derived from the North American lineage . Althoug...

  Abstract Influenza pandemics arise when novel influenza virus subtypes emerge in populations with little or no pre-existing immunity . The recent expansion of H5N1 virus circulation in mammals — including documented spread in cattle and sporadic human infections — coupled with the emergence of mutations associated with enhanced pandemic potential , underscores the persistent threat of novel influenza strains. Pandemic preparedness critically depends on developing effective vaccines capable of providing broad protection across diverse viral strains. While vaccination remains the most effective strategy for preventing influenza and its complications, pandemic vaccine development faces substantial challenges . These include the rapid mutation rates characteristic of influenza viruses, driven by error-prone RNA replication, broad host range, environmental selection pressures, and frequent genetic recombination. Such factors complicate predictions of which strain will trigger the next...

  Abstract Infectious diseases are often observed to have different epidemiology in different countries , which arises due to various factors including those that are ecological, socioeconomic, and healthcare-related . Such variability can sometimes be best captured through looking at groups of countries that are similar within-group but variable between-group. In this study we use statistical learning methods to generate data-driven disease-centric groupings of countries rather than those developed for administrative or political reasons by e.g. the WHO, World Bank, and the United Nations. In particular, we apply hierarchical clustering to group countries based on shared disease-relevant characteristics for zoonotic H5N1 influenza . Using statistical methods such as classification and regression trees (CART)-based imputation and dynamic tree cutting, the analysis accounts for missing data and identifies epidemiologically (rather than politically or economically) meaningful cluster...

  September 2025   The development of influenza candidate vaccine viruses (CVVs), coordinated by WHO, remains an essential component of the overall global strategy for influenza pandemic preparedness . Selection and development of CVVs are the first steps towards timely vaccine production and do not imply a recommendation for initiating manufacture . National authorities may consider the use of one or more of these CVVs for pilot lot vaccine production , clinical trials and other pandemic preparedness purposes based on their assessment of public health risk and need.  Zoonotic influenza viruses continue to be identified and evolve both antigenically and genetically, leading to the need for additional CVVs for pandemic preparedness purposes.  Changes in the antigenic and genetic characteristics of these viruses relative to existing CVVs and their potential risks to public health justify the need to develop new CVVs. This document summarizes the antigenic and genetic c...

  Abstract The SARS outbreak and influenza A(H5N1) infections (2003–2004) prompted WHO to establish a global influenza antiviral stockpile , enabling rapid distribution to 72 countries during the 2009 A(H1N1) pandemic. To improve access in low- and middle-income countries, WHO added antivirals to the WHO Model List of Essential Medicines and included them in the Prequalification Programme . The 2011 Pandemic Influenza Preparedness Framework refined strategies for equitable access and rapid response. Lessons from COVID-19 led to a new WHO-led mechanism—the Interim Medical Countermeasures Network (i-MCM-net)— which supports integrated supply chains, real-time data sharing, research and development, and equitable access. WHO continues to emphasise equity and global solidarity , highlighting the need for accessible, effective, and affordable antivirals alongside vaccines to protect vulnerable populations and mitigate the impact of future pandemics. Source: Journal of Infectious Disease...

  Abstract Influenza antivirals play an important role in the prevention and control of influenza. We reviewed data on the effectiveness of influenza antivirals for reducing influenza transmission . We found that antiviral prophylaxis , whether given pre- or postexposure , has been shown to reduce the risk of symptomatic influenza in a variety of settings and populations . During pandemic responses, antiviral prophylaxis could play an important role, as demonstrated by the use of amantadine in the 1968–1969 influenza A(H3N2) pandemic and oseltamivir during the 2009–2010 influenza A(H1N1)pdm09 pandemic. Antiviral treatment reduces symptom severity, prevents complications, and can reduce onward transmission of infection. However, resistance, accessibility, and timing pose challenges. Future research directions include innovative therapies and combination treatments. Continued research and stewardship are crucial to optimize antiviral impact. Source: Journal of Infectious Diseases,...

  Abstract Highly pathogenic avian influenza A(H5) viruses globally impact wild and domestic birds, and have caused severe infections in mammals, including humans , underscoring their pandemic potential . The antigenic evolution of the A(H5) haemagglutinin (HA) poses challenges for pandemic preparedness and vaccine design . Here the global antigenic evolution of the A(H5) HA was captured in a high-resolution antigenic map . The map was used to design immunogenic and antigenically central vaccine HA antigens, eliciting antibody responses that broadly cover the A(H5) antigenic space. In ferrets , a central antigen protected as well as homologous vaccines against heterologous infection with two antigenically distinct viruses. This work showcases the rational design of subtype-wide influenza A(H5) pre-pandemic vaccines and demonstrates the value of antigenic maps for the evaluation of vaccine-induced immune responses through antibody profiles. Source: Nature,  https://www.nature.c...

Abstract Highly pathogenic avian influenza H5Nx viruses are an emerging threat for global health, especially clade 2.3.4.4b H5N1 virus which causes panzootic infections . Here we describe the isolation and characterization of broadly cross-neutralizing monoclonal antibodies (mAbs) against diverse H5Nx viruses from individuals who received a monovalent H5N1 vaccine 15 years ago . By screening over 500 mAbs, we identified 5 mAbs that neutralized the majority of H5 clades including 2.3.4.4b and target three distinct conserved epitopes within the HA globular head. Cryo-electron microscopy structures of these mAbs in complex with HA, deep mutational scanning and neutralization escape studies define the sites of vulnerability of H5 HA. These mAbs mediated stronger prophylactic protection against clade 2.3.4.4b H5N1 infection in mice than the best-in-class mAb targeting the HA stem. Our study identified several highly potent broadly neutralizing H5 mAbs from humans that either alone or in com...

  New human cases {1,2}:  -- From 26 August to 29 September 2025 , based on reporting date, the detection of influenza A(H5) in one human , influenza A(H5N1) in one human , influenza A(H9N2) in eight humans and an influenza A(H1N1) variant ((H1N1)v) virus in one human were reported officially.   Circulation of influenza viruses with zoonotic potential in animals :  -- High pathogenicity avian influenza (HPAI) events in poultry and non-poultry animal species continue to be reported to the World Organisation for Animal Health (WOAH).{3}  -- The Food and Agriculture Organization of the United Nations (FAO) also provides a global update on avian influenza viruses with pandemic potential.{4}  Risk assessment {5}:  -- Sustained human to human transmission has not been reported from these events.  -- Based on information available at the time of this risk assessment update , the overall public health risk from currently known influenza A viruses d...

  Highlights •  UniFluVec, an H1N1pdm vaccine candidate , includes NS1 and NEP modifications to boost attenuation and immunity. •  UniFluVec protects ferrets from H5N1 , enhancing clearance, limiting lung damage, and ensuring 100 % survival after one dose. •  Replication-deficient UniFluVec shows cross-protection , supporting its potential as a pre-pandemic intranasal vaccine. Abstract Background The emergence of new influenza strains with unpredictable antigenic properties poses a significant vaccination challenge. The increasing incidence of human H5 infections underscores the urgent need for effective pre-pandemic vaccines. Methods The UniFluVec and UniFluVec-wtNS1 viruses were designed as H1N1pdm vaccine candidates . Both viruses contained a heterologous A/Singapore/1/57-like (H2N2) NEP gene , which served as an attenuation factor . UniFluVec additionally carried a truncated to 124 amino acids NS1 gene , and an insertion of conserved influenza sequences. UniFluVe...

  Abstract In China, low pathogenic avian influenza (LPAI) H3N8 virus is widespread among chickens and has recently caused three zoonotic infections , with the last one in 2023 being fatal . Here we evaluated the relative pandemic risk of this 2023 zoonotic H3N8 influenza virus, utilizing our previously published decision tree. Serological analysis indicated that a large proportion of the human population does not have any cross-neutralizing antibodies against this H3N8 strain. LPAI H3N8 displayed a dual affinity for a2-3 and a2-6 sialic acids and replicated efficiently in human bronchial epithelial cells . Furthermore, we observed H3N8 transmission via direct contact but not aerosols to ferrets with pre-existing H3N2 immunity. Although pre-existing H3N2 immunity resulted in a shortened disease course in ferrets, it did not reduce disease severity or replication in the respiratory tract. This study suggests that this zoonotic H3N8 strain has moderate pandemic potential and emphasiz...

  Abstract In 2024, a human infection with clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) virus was identified in the United States in an individual with no known exposure . Genetic analysis revealed two hemagglutinin (HA) substitutions, P136S and A156T, which may alter viral antigenicity . Virus isolation was unsuccessful, preventing timely serologic analysis. To overcome this limitation, we generated recombinant viruses by reverse genetics and characterized the effects of the substitutions on antigenicity, receptor binding , and replicative fitness. The A156T substitution introduced a potential N-linked glycosylation site , resulting in altered antigenicity and reduced replication in primary human nasal epithelial cells and ferrets . Importantly, the A(H5N1) candidate vaccine virus (CVV) IDCDC-RG80A, which possesses HA-T156, remained antigenically effective against viruses with and without these substitutions. These findings highlight the importance of sequencing, rever...

  {Excerpt} Highly pathogenic avian influenza caused by H5N1 viruses emerged in East Asia in the late 1990s and spread to Europe, Africa, and the Middle East , circulating in wild and domestic birds and occasionally spilling over into mammals and humans . These viruses are classified into genetic lineages called clades based on differences in the gene encoding hemagglutinin , a key surface protein involved in cell entry. In 2021, one such lineage, clade 2.3.4.4b , crossed from Europe to Canada . It spread rapidly, reaching the southern tip of South America in less than 2 years and causing massive mortality in seabirds and marine mammals , including South American sea lions (Otaria flavescens) and southern elephant seals (Mirounga leonina) (1). However, human mortality has been markedly lower in the present H5N1 outbreak than in past ones. If the virus evolves the capacity to transmit from human to human, understanding this reduction will be essential for mounting an effective respo...