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Editor’s summary High-pathogenicity avian influenza subtype H5N1 is now present throughout the US , and possibly beyond. More cattle infections elevate the risk of the virus evolving the capacity to transmit between humans , potentially with high fatality rates . Nguyen et al. show that from a single transmission event from a wild bird to dairy cattle in December 2023, there has been cattle-to-poultry, cattle-to-peridomestic bird , and cattle-to-other mammal transmission. The movement of asymptomatic dairy cattle has facilitated the rapid dissemination of H5N1 from Texas across the US . Evolution within cattle, assessed using deep-sequencing data, has detected low-frequency sequence variants that had previously been associated with mammalian adaptation and transmission efficiency. —Caroline Ash Structured Abstract INTRODUCTION Highly pathogenic avian influenza (HPAI) viruses have critical consequences for animal health and the agricultural economy—and may have pandemic potential. HPAI ...

ABSTRACT Avian influenza is one of the major threats to poultry and human health in northern Benin , while mixed-species farming systems increase the risks of viral transmission. The present study estimated the seroprevalence of avian influenza subtypes H9N2 and H5 in indigenous chickens and guinea fowls in the Atacora and Donga regions. A total of 300 birds including 191 indigenous chickens and 109 guinea fowls, from six districts were sampled through a cross-sectional survey using systematic random sampling. Hemagglutination inhibition assay was used to detect antibodies, revealing an overall H9N2 seroprevalence of 41%, with 17.5% of samples testing positive for H5 . The seroprevalence of H9N2 was notably higher in guinea fowls (51.81% in Atacora and 52% in Donga) compared to chickens (34.95% in Atacora and 34.83% in Donga). H5 antibodies were found only in guinea fowls in Atacora (46.66%). The study also found that farms with both chickens and guinea fowls had a significantly higher...

Abstract In 2018, a clinical trial of four investigational therapies for Ebola virus disease (EVD), known as the PALM trial , was conducted in the Democratic Republic of Congo . All patients received either the antiviral remdesivir (RDV) or a monoclonal antibody product : ZMapp, mAb114 (Ebanga), or REGN-EB3 (Inmazeb). The study concluded that both mAb114 and REGN-EB3 were superior to ZMapp and RDV in reducing mortality from EVD. However, the data suggested that some patients in the RDV and ZMapp groups might have been sicker at the time of treatment initiation. Here, we assessed the efficacy of each of these therapies in a uniformly lethal rhesus monkey model of EVD when treatment was initiated 5 days after Ebola exposure. Treatment with RDV, mAb114, REGN-EB3, and ZMapp each resulted in similar survival (approximately 40% ). Survival was associated with circulating viral load at treatment initiation. A trend of more escape mutants in the GP1 and GP2 domains was observed for the mAb114 ...

Abstract H5Nx clade 2.3.4.4b high-pathogenicity avian influenza viruses (HPAIVs) have decimated wild bird and poultry populations globally since the autumn of 2020. In the United Kingdom (UK) and in continental Europe , the H5N8 subtype predominated during the first epizootic wave of 2020/21, with few detections of H5N1 . However, during the second (2021/22) and third (2022/23) epizootic waves , H5N1 was the dominant subtype. The rapid shift in dominance from H5N8 to H5N1 was likely driven by a combination of virological, immunological, and/or host-related factors . In this study, we compared viral fitness and immunological responses in ducks , a key reservoir species, using dominant genotypes of H5N1 (genotype AB) and H5N8 (genotype A) from the second wave. While viral shedding dynamics were similar for both viruses, H5N8 was more pathogenic . Antigenic analysis of post-infection duck sera revealed that the haemagglutinin (HA) protein was antigenically similar across clade 2.3.4.4b H5...

Abstract Background Baloxavir marboxil (baloxavir) rapidly reduces influenza virus shedding , which suggests that it may reduce transmission. Studies of treatment with neuraminidase inhibitors have not shown sufficient evidence that they prevent transmission to contacts. Methods We conducted a multicountry, phase 3b trial to assess the efficacy of single-dose baloxavir treatment to reduce influenza transmission from index patients to household contacts. Influenza-positive index patients 5 to 64 years of age were randomly assigned in a 1:1 ratio to receive baloxavir or placebo within 48 hours after symptom onset. The primary end point was transmission of influenza virus from an index patient to a household contact by day 5. The first secondary end point was transmission of influenza virus by day 5 that resulted in symptoms. Results Overall, 1457 index patients and 2681 household contacts were enrolled across the 2019–2024 influenza seasons; 726 index patients were assigned to the baloxa...