leptospirosis vaccine

Novel Target for Pathogenic Leptospira Detection via Colorimetric Loop-Mediated Isothermal Amplification (LAMP): Development, Validation, and Comparative Analysis.

Ghoraishizadeh Peyman P, Clemente Benjie B, Saimuang Kween K, Lertjuthaporn Sakaorat S et al.

Leptospirosis is a globally prevalent zoonotic disease that remains challenging to diagnose due to its nonspecific symptoms and the limitations of current diagnostic methods and targets. To address these challenges, we developed and validated a naked-eye loop-mediated isothermal amplification (LAMP) assay targeting the newly identified orpH region for the rapid detection of pathogenic Leptospira species. Comparative genomic analysis identified orpH as a conserved sequence among pathogenic Leptospira. A colorimetric LAMP assay (LAMP-orpH) was developed and evaluated using reference strains and serum samples obtained from patients with suspected leptospirosis. The diagnostic performance of the assay on these serum samples was evaluated in comparison with conventional PCR and the microscopic agglutination test (MAT), with the real-time PCR assay targeting lipL32 designated as the reference standard. The LAMP-orpH assay demonstrated 87.2% sensitivity and 94.8% specificity among 76 suspected cases and 29 controls, showing strong agreement with real-time PCR (κ = 0.826). It outperformed MAT (63.8% sensitivity) and conventional PCR (23.4% sensitivity), achieving a detection limit of 102 cells/mL in spiked serum. The LAMP-orpH assay offers a rapid, sensitive, and specific tool for early leptospirosis diagnosis. Its simple colorimetric readout and minimal equipment requirements make it ideal for use in rural and resource-limited settings, providing a practical alternative to MAT, conventional PCR, and qPCR.

Immunogenicity and protective efficacy of recombinant BCG expressing a multi-epitope vaccine against mycobacterium tuberculosis.

Zhang Xuan-Ji XJ, Luo Jia-Rui JR, Tian Ting-Ting TT, Shi Juan J et al.

Mycobacterium tuberculosis (Mtb) infects approximately one-quarter of the global population, of whom 5%-10% develop active tuberculosis (TB). Although Bacillus Calmette-Guérin (BCG) remains the cornerstone vaccine against severe infant TB, its efficacy in adults is limited, underscoring the need for novel TB vaccines. This study aimed to design a multi-epitope vaccine, tMEV, and validate its protective potential through bioinformatic prediction and in vivo experiments. tMEV was constructed from dominant T- and B-cell epitopes derived from Mtb ESAT-6, PE35, PPE38, and PE4 proteins, fused with an adjuvant. Its vaccine candidacy was assessed via physicochemical and solubility profiling, secondary and tertiary structure modeling, TLR-4 molecular docking, molecular dynamics simulation, and immune simulation. The tMEV coding sequence was cloned into pMV361 and transformed into BCG to generate recombinant BCG (rBCG-tMEV). Immunogenicity, antigenicity, and protective efficacy were evaluated in mouse immunization and Mtb challenge models. tMEV exhibited favorable vaccine-like properties in silico. In mice, both tMEV and rBCG-tMEV induced Mtb-specific immune responses. Compared with PBS, tMEV significantly enhanced cellular and humoral immunity with a Th2-biased profile. Relative to conventional BCG, rBCG-tMEV elicited a superior mixed Th1-Th2 response and higher antigen-specific immunity, accompanied by increased secretion of IFN-γ, IL-2, TNF-α, granzyme B, and perforin. Moreover, rBCG-tMEV markedly reduced bacterial loads in the lungs and spleens of Mtb-infected mice, conferring partial protection. These findings demonstrate that tMEV and rBCG-tMEV possess robust immunogenicity and protective potential against Mtb, representing promising novel TB vaccine candidates and providing a rationale for future vaccine development and optimization.

Correction to "Screening Natural Cholesterol Analogs to Assemble Self-Adjuvant Lipid Nanoparticles for Antigens Tagging Guided Therapeutic Tumor Vaccine".

A Phase 1/2 Trial Evaluating the Safety and Immunogenicity of an mRNA-based Seasonal Influenza Vaccine Candidate Encoding Hemagglutinin and Neuraminidase.

De Coster Ilse I, Cardona Jose F JF, Ferguson Murdo M, Leroux-Roels Isabel I et al.

Hemagglutinin (HA) is the principal immunologic target of most licensed seasonal influenza vaccines. Targeting both HA and neuraminidase (NA) might improve vaccine effectiveness. This randomized phase 1/2 study evaluated an investigational mRNA-based quadrivalent seasonal influenza vaccine, encoding HA and NA of A/H1N1, A/H3N2, B/Victoria, and B/Yamagata (FLUm4HA-4NA). In phase 1, adults aged 18-50 years received either one of twelve mRNA vaccine formulations of varying HA-only or HA and NA mRNA doses, or a licensed quadrivalent seasonal influenza comparator. In phase 2, participants aged 18-64 years (younger adults) and 65-85 years (older adults) received FLUm4HA-4NA (three groups per age category, with different HA/NA mRNA doses) or age-appropriate licensed quadrivalent comparator. Primary endpoints were safety/reactogenicity, and hemagglutination inhibition [HI] and NA inhibition [NI] responses against the four seasonal strains at day 29. Cross-reactive HI/NI responses against drifted strains, virus neutralization, and HA-/NA-specific cell-mediated immunity were evaluated in phase 2 as tertiary objectives. A total of 293 participants (21-25 per group) were vaccinated in phase 1, 480 younger (108-137 per group) and 483 older adults (117-125 per group) in phase 2. Solicited events were more frequent with FLUm4HA-4NA than comparators and were mostly short-lived and mild or moderate. No deaths or vaccine-related serious adverse events were reported. Post-vaccination HI and neutralizing titers in the FLUm4HA-4NA groups were similar or higher for the A strains and lower for the B strains versus comparators. NI responses exceeded those of comparators for all four strains. HI and NI titers against evaluated drifted A strains were similar or higher after FLUm4HA-4NA than after comparator vaccination. HA-specific CD4+ and CD8+ T-cell responses were generally higher after FLUm4HA-4NA than comparator vaccination. FLUm4HA-4NA showed an acceptable safety profile and humoral and cellular immunogenicity in the study population, supporting further development and formulation optimization to improve influenza B HI responses. ClinicalTrials.gov: NCT05823974; euclinicaltrials.eu: 2022-502308-66-00.