influenza vaccine

Co-circulation of H5N1 and H5N6 High Pathogenicity Avian Influenza Viruses in Migratory Birds at a Coastal Wintering Site in China.

Hu Xinyu X, Xiang Haiyang H, Wang Wenhao W, Kong Yunyi Y et al.

Since 2020, H5Nx high Pathogenicity avian influenza viruses (HPAIVs) belonging to hemagglutinin (HA) clade 2.3.4.4b have undergone widespread dispersal in wild birds, posing substantial threats to global poultry populations and mammals worldwide. In this study, we report the co-circulation of clade 2.3.4.4b H5N1 and H5N6 HPAIVs associated with mortality events in Anseriformes and Charadriiformes at a coastal wintering site in Fujian Province, China. H5N1 and H5N6 viruses were identified in 4 species of waterfowl (Bean Goose, Eastern Spot-billed Duck, Eurasian Wigeon, and Eurasian Curlew). Phylogenetic analysis indicated that these H5N1 and H5N6 isolates were clade 2.3.4.4b strains circulating within Eurasia and lacked known mammalian adaptation markers in key proteins. The infected birds exhibited severe systemic multi-organ pathology, with the most pronounced damage observed in the lungs. H5N6 and H5N1 viruses caused lethal injury in BALB/c mice, with H5N1 leading to systemic infection. Environmental sampling also revealed the presence of H5N1 HPAIVs alongside low-pathogenicity avian influenza viruses (LPAIVs) such as H3N1 and H6N1. Our findings highlight the complex and dynamic transmission patterns of H5 HPAIV in wild bird populations and the substantial threat they pose to mammals, underscoring the critical importance of sustained surveillance for high pathogenicity avian influenza in wild birds.

A subunit vaccine protects A129 mice from death and joint swelling against lethal Chikungunya virus challenge.

Li Jiangfan J, Fang Ting T, Song Liyuan L, Qiang Li L et al.

Chikungunya virus (CHIKV) is primarily transmitted to humans through bites of infected Aedes mosquitoes, causing febrile illness as well as acute or chronic arthritis. With increasing reports in previously non-endemic regions, it poses an emerging threat to public health and a growing risk to travelers. Despite the recent approval of live-attenuated and virus-like particle-based vaccines, a safe, efficacious, and cost-effective vaccine remains urgently needed. The envelope glycoproteins E1 and E2, which play crucial roles in viral attachment and entry, are the major immunodominant structural proteins and can effectively elicit protective antibodies. We engineered mammalian cells to produce the ectodomains of the E1 and E2 glycoproteins and evaluated the protective efficacy of the resulting vaccine formulations in vivo. A two-dose vaccination regimen elicited high levels of antibodies and provided full protection against lethal challenge in A129 mice, preventing both death and joint swelling. These findings demonstrate the potential of this vaccine candidate against CHIKV and warrant its further development.

NMR-Based Structural Elucidation of a New Dihydroisocoumarin and Related Polyketides From a Mangrove-Derived Fusarium sp.

García-Oceguera Evelyn E, Fajardo-Hernández Carlos A CA, Loa-Ramírez Ixchel A IA, Morales-Jiménez Jesús I JI et al.

Antimicrobial resistance (AMR) remains one of the greatest global public health challenges of the 21st century, compromising the effectiveness of current therapies and highlighting the urgent need for new antibacterial agents. Natural products from bacteria and filamentous fungi continue to represent an invaluable source of structurally diverse bioactive metabolites. In this study, a library of 56 extracts obtained from mangrove-associated ascomycetes was screened against a panel of multidrug-resistant bacterial pathogens. Bioactivity data were integrated with LC-MS/MS-based molecular networking to prioritize extracts for chemical investigation. This approach identified Fusarium sp. IQ-1921 as one of the most promising candidates, leading to the isolation of a new dihydroisocoumarin (1) and four known analogues (2-5). The structures of all isolated metabolites were elucidated by 1D and 2D NMR spectroscopy and high-resolution mass spectrometry (HRMS). All compounds were evaluated against multidrug-resistant strains of Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus. Compounds 1 and 3-5 exhibited moderate antibacterial activity, with compound 1 displaying the broadest inhibitory profile. These findings demonstrate the effectiveness of integrating metabolomics with bioactivity-guided prioritization for the discovery of antibacterial natural products and further highlight the indispensable role of NMR spectroscopy in the structural elucidation of closely related fungal metabolites.

[Strategies to address vaccine hesitancy in Brazil: evidence synthesis].

Marques Ana Paula da Costa APDC, Gubert Vanessa Terezinha VT, Dias Adriano da Costa ADC, Gasparoto Antonio Luiz Dal Bello ALDB et al.