Search Results (198)

Bacterial β-barrel pore-forming toxins, including Staphylococcus aureus α-toxin (Hla) and Bacillus cereus toxins hemolysin II (HlyII) and cytolytic toxin K2 (CytK-2), are secreted by bacterial cells as water-soluble monomers. These monomers assemble within lipid bilayers to form cylindrical pores, leading to lysis of target eukaryotic cells. We created mutant forms of these toxins that, based on the results of X-ray structural analysis of Hla and the prediction of the 3D structure of HlyII and CytK2, can form intramolecular disulfide bonds in monomers. The substitutions were made in the region responsible for toxin insertion into the target membrane. The mutant forms reversibly altered their hemolytic activity depending on the presence of reducing reagents and were non-toxic when injected into experimental animals. The immune response to injection of the mutant forms of Hla and CytK-2 toxins resulted in higher antibody titers against the wild-type toxins and a higher level of immunological memory than with injection of the HlyII mutant. The mutant form of CytK-2 demonstrates the properties of a prototype vaccine, as immunization with this protein protects animals against the effects of the wild-type toxin. Full article

Background: Blockchain is increasingly proposed to strengthen pharmaceutical traceability, anti-counterfeiting, and chain of custody in multi-actor supply chains, but the evidence base remains heterogeneous in technical rigor and operational clarity. Methods: We conducted a mapping review of Scopus and Web of Science to map publication patterns, identify dominant thematic configurations, and compare citation-salient studies across recurring solution profiles and operational design dimensions. The final corpus comprised 103 records. Results: The literature expanded rapidly from 2019 to 2025, with notable geographic concentration and dissemination mainly through technically focused outlets. Keyword analysis identified a core traceability theme, an implementation stream centered on smart contracts, Ethereum, and security, and additional streams involving vaccines and regulatory or credentialing concerns. Citation-salient studies clustered into implemented systems and prototypes, architecture or framework proposals, and contextual maturity or decision-layer evidence. Across these profiles, transferability depended less on platform choice than on governance and access-control assumptions, modular smart contract roles, and verifiable on-chain/off-chain data placement. Conclusions: Chain-of-custody semantics and evaluation methods remain inconsistently formalized, limiting cross-study comparability and the interpretability of operational claims. Benchmark-oriented assessments and minimal reporting standards specifying governance parameters, logistics scope and checkpoints, workload, measurement conditions, and concrete evidence artifacts are needed. Full article

Canine monocytotropic ehrlichiosis (CME), caused by the intracellular bacterium Ehrlichia canis, is a significant tick-borne disease in dogs that requires effective vaccination strategies. This study aimed to evaluate recombinant TRP19 (rTRP19), a highly conserved immunodominant antigen, as a promising vaccine candidate against experimental E. canis infection in dogs, following its success in a mouse model. Fifteen E. canis-negative beagles were immunized intramuscularly with either 50-µg or 100-µg of rTRP19 in alum adjuvant or a PBS control, on days 0, 30, and 60. All dogs were then exposed intravenously to E. canis on day 90 and monitored for 120 days for clinical signs, hematological changes (platelet count, hematocrit, and body temperature), and antibody titers. The rTRP19 vaccine prototypes induced strong antigen-specific humoral responses. They caused a significant reduction in rickettsial load, with complete elimination observed in the 100-µg group by day 7 and in both vaccinated groups by day 14 of exposure. Furthermore, the mean body temperature in the 100-µg rTRP19 group was significantly lower than that of the control group, suggesting that the higher-dose vaccine mitigated febrile response. Collectively, these results suggest that rTRP19 vaccine prototypes hold promise in overcoming the clinical signs and hematological abnormalities of E. canis infection by inducing a strong antigen-specific antibody response. Full article

Endocervical adenocarcinoma is now classified within an etiologic framework based on the presence or absence of high-risk human papillomavirus (HPV) infection. Gastric-type endocervical adenocarcinoma (GAS) is the prototypical HPV-independent subtype, accounting for up to 25% of endocervical adenocarcinomas and showing a particularly high frequency in East Asia. GAS is typically diagnosed at a more advanced stage than usual-type HPV-associated endocervical adenocarcinoma (UEA); exhibits deep stromal and parametrial invasion, lymphovascular space invasion, and a strong propensity for ovarian and peritoneal metastasis; and is associated with markedly worse survival, even in stage I disease. Radiological evaluation is challenging because of diffuse infiltrative growth, prominent mucin production, and frequent underestimation of extra-cervical spread. Histologically, GAS shows gastric-type (pyloric) differentiation, ranging from minimal deviation adenocarcinoma to poorly differentiated forms, and often overlaps with precursor lesions such as atypical lobular endocervical glandular hyperplasia and gastric-type adenocarcinoma in situ. Immunophenotypically, GAS is typically p16-negative, ER/PR-negative, and frequently exhibits mutant-type p53 and expression of gastric markers including MUC6, HIK1083, and claudin 18.2. Recent next-generation sequencing and multi-omics studies have revealed recurrent alterations in TP53, CDKN2A, STK11, KRAS, ARID1A, KMT2D, and homologous recombination-related genes, together with the activation of PI3K/AKT, WNT/β-catenin, TGF-β, and EMT pathways and characteristic metabolic reprogramming. GAS is highly resistant to conventional chemotherapy and radiotherapy, and its current management follows guidelines for squamous and usual-type adenocarcinoma. Emerging data support precision-medicine approaches targeting HER2/HER3, PD-1/PD-L1, and claudin 18.2, and suggest a role for PARP inhibition and other genotype-directed therapies in selected subsets. Given its aggressive biology and rising relative incidence in the HPV-vaccination era, GAS represents a critical unmet need in gynecologic oncology. Future progress hinges on developing reliable diagnostic biomarkers, refining imaging protocols, and validating targeted therapies through international clinical trials. Full article

Background/Objectives: While tick-borne encephalitis virus (TBEV) is genetically relatively conserved, the significant antigenic divergence between its main circulating subtypes hinders the development of broadly effective antiviral treatments and vaccines. Current inactivated TBEV vaccines offer limited cross-protection against heterologous strains, as evidenced by cases among vaccinated individuals in endemic regions. The aim of this study was to design a candidate mRNA vaccine and evaluate the breadth of protective immunity it elicits. Methods: Ten candidate mRNA-PrM/E-LNP vaccines were comparatively evaluated for immunogenicity and protective efficacy in BALB/c mice. Immunogenicity was assessed by measuring antigen-specific IgG titers via ELISA and neutralizing antibody titers against a panel of TBEV strains using a virus-neutralization test. Protective efficiency was determined in a lethal challenge model, where immunized mice were challenged with one of seven distinct TBEV strains. Results: Vaccination with all tested mRNA-PrM/E-LNP candidates conferred 100% survival in mice following a lethal challenge with each of the seven TBEV strains (100 LD₅₀). The construct mRNA-PrM/E—Krasny Yar-8 demonstrated the highest immunogenicity, inducing antigen-specific antibodies with a geometric mean titer (GMT) of 1:6625, as well as the broadest virus-neutralizing activity against both homologous and heterologous TBEV strains in vitro. Conclusions: The mRNA platform represents a promising strategy for developing TBEV vaccines, demonstrating high immunogenicity and cross-protective efficacy against diverse viral strains. Full article

This research paper presents a smart IoT-based COVID-19 vaccine supply chain, monitoring, and control system. This proposed system is designed to efficiently and effectively monitor COVID-19 vaccine storage sites by tracking their temperature, humidity, quantity, and location on a map across various supply chain categories. It ultimately aims to monitor and control temperatures outside the range at the tracked location. The approach utilized temperature, humidity, and ultrasonic sensors, a GPS module, a Wi-Fi module, and an Arduino Uno microcontroller. The system was designed and implemented using Arduino and Proteus integrated design environments (IDEs) and coded using the embedded C/C++ programming language. A real-life working system prototype was designed and implemented. The measured sensor readings can be viewed via a computer system capability or any mobile device, such as an Android phone, iPhone, iPad, or laptop, with the aid of a cloud-based platform, namely, Thingspeak.com. The experimentally measured sensor readings are stored in a data log file for subsequent download and analysis whenever the need arises. The data aggregation and analytics are coded using MATLAB and viewed as charts, and the location map of vaccine carrier coordinates is sent to the web cloud for tracking. An alarm message is sent to the monitoring and control system if an unfavorable vaccine environment exists in either the store or the carrier container. A suitable sensor-based interface architecture and web portal are provided, allowing health practitioners to remotely monitor the vaccine supply chain system. This method encourages health workers by reducing the high levels of supervision required by vaccine supervisors to ensure the smooth supply of vaccines to vaccine collection centers, by using a wireless sensor network and IoT technology. Experimental results from the implemented system prototype demonstrated the benefits of the proposed approach and its possible real-life health monitoring applications. Full article

Porcine epidemic diarrhea (PED), a severe and highly contagious disease induced by porcine epidemic diarrhea virus (PEDV), impacts pigs across all age groups but has a particularly high lethality in neonatal piglets, with mortality rates reaching 80 to 100%, leading to substantial economic losses in the swine industry. In this investigation, 128 intestinal samples obtained from 65 large-scale pig farms in eight prefectures of Guangdong Province were screened by RT-qPCR between 2022 and 2024. Of these, 50 samples (39.06%) tested positive for Porcine Epidemic Diarrhea Virus (PEDV). The complete S1 genes of 31 representative strains were sequenced. Phylogenetic analysis revealed G2c as the exclusive dominant lineage (29/31, 93.6%), with single representatives of G2a and G2d. Nucleotide identity among the local strains ranged from 88.9 to 100% and 88.1 to 93.5% to prototype CV777 and from 91.2 to 99.1% to vaccine strain AJ1102. The COE neutralizing epitope (aa 499–638) carried 26 substitutions versus AJ1102; T499I/S, A520S/L, F539L, K566N and F615L were most prevalent. The SS2 epitope was fully conserved, whereas SS6 showed three low-frequency changes (S766P, S769F, G770V). Six distinct N-glycosylation patterns were identified relative to AJ1102. The predominance of G2c, accompanied by marked epitope drift and altered glycosylation, indicates the need for further investigation into vaccine efficacy. Continuous surveillance and the careful evaluation of G2c-based vaccine candidates are warranted. Full article

The COVID-19 pandemic, driven by SARS-CoV-2, continues to challenge global health due to emerging variants and the potential risk posed by related sarbecoviruses. Neutralizing antibodies targeting the spike (S) glycoprotein, particularly the receptor-binding domain (RBD), play a crucial role in viral neutralization and vaccine design. Although broadly neutralizing anti-RBD antibodies have been identified, the nature of cross-reactive humoral responses induced by natural infection with ancestral SARS-CoV-2 strains remains incompletely understood. Here, we isolated 105 S-specific monoclonal antibodies (mAbs) from individuals recovered from prototype SARS-CoV-2 infection. Of these, 30 mAbs cross-recognized SARS-CoV-1, including 25 RBD-directed mAbs, of which 12 displayed cross-neutralizing activity against both viruses. Among them, mAb 12C2 potently neutralized SARS-CoV-1 and multiple SARS-CoV-2 variants, likely through mechanisms that include inhibition of membrane fusion and potential destabilization of the S trimer. Cryo-electron microscopy revealed that 12C2 engages the outer face of the RBD, overlapping with the epitope recognized by the broadly neutralizing antibody S309 derived from SARS-CoV-1 convalescent. Collectively, these findings demonstrate that ancestral SARS-CoV-2 infection can elicit robust cross-neutralizing antibody responses and provide valuable insights for the design of broadly protective antibodies and vaccines. Full article

Porcine adenovirus serotype 5 (PAdV-5) is an emerging viral vector platform for veterinary vaccines; however, its genomic plasticity and essential replication elements remain incompletely characterized. This study reports the isolation and reverse genetic manipulation of a novel PAdV-5 strain (GD84) from diarrheic piglets in China. PCR screening of 167 clinical samples revealed a PAdV-5 detection rate of 38.3% (64/167), with successful isolation on ST cells after three blind passages. The complete GD84 genome is 32,620 bp in length and exhibited 99.0% nucleotide identity to the contemporary strain Ino5, but only 97.0% to the prototype HNF-70. It features an atypical GC content of 51.0% and divergent structural genes—most notably the hexon gene (89% identity to HNF-70)—suggesting altered immunogenicity. Using Red/ET recombineering, we established a rapid (less than 3 weeks) reverse genetics platform and generated four E3-modified recombinants: ΔE3-All-eGFP, ΔE3-12.5K-eGFP, ΔE3-12.5K+ORF4-eGFP, and E3-Insert-eGFP. Crucially, the ΔE3-All-eGFP construct (complete E3 deletion) failed to be rescued, while constructs preserving the 12.5K open reading frame (ORF) yielded replication-competent viruses with sustained eGFP expression over three serial passages and titers over 10^7.0 TCID₅₀/mL. Fluorescence intensity was inversely correlated with genome size, as the full-length E3-Insert-eGFP virus showed reduced expression compared with the ΔE3 variants. Our work identifies the 12.5K ORF as essential for PAdV-5 replication and provides an optimized vaccine engineering platform that balances genomic payload capacity with replicative fitness. Full article

Dengue is a rapidly spreading mosquito-borne viral infection, with increasing reports of outbreaks globally. According to the World Health Organization (WHO), by 30 April 2024, over 7.6 million dengue cases were reported, including 3.4 million confirmed cases, more than 16,000 severe cases, and over 3000 deaths. As dengue remains endemic in many regions, there is a critical need for the development of new vaccines and manufacturing processes that are efficient, cost-effective, and capable of meeting growing demand. In this study, we explore an alternative process development pathway for the future manufacturing of a dengue vaccine, utilizing Komagataella phaffii (Pichia pastoris) as the host organism, one of the most promising candidates for the expression of heterologous proteins in vaccine development. It combines the speed and ease of highly efficient prokaryotic platforms with some key capabilities of mammalian systems, making it ideal for scalable and cost-effective production. The key outcomes of our research include (i) demonstrating the versatility of the Komagataella phaffii platform in the production of dengue viral-like particles (VLPs); (ii) optimizing the culture process using Design of Experiments (DoE) approaches in small-scale bioreactors; (iii) developing a novel purification platform for enveloped VLPs (eVLPs), and (iv) establishing alternative biophysical characterization methods for the dengue vaccine prototype. These findings provide a promising foundation for efficient and scalable production of dengue vaccines, addressing both technical and operational challenges in vaccine manufacturing. Full article

Authorized SARS-CoV-2 vaccines elicit both antibody and T-cell responses; however, benchmark correlates and update decisions have largely emphasized neutralizing antibodies. Motivated by the complementary role of cellular immunity, we designed a prototype polyepitope DNA vaccine encoding conserved human and mouse T-cell epitopes from non-structural proteins of the original strain SARS-CoV-2 lineage. Epitope selection was guided by in silico predictions for common HLA class I alleles in the Brazilian population and the mouse H-2Kb haplotype. To enhance immunogenicity, the polyepitope sequences were fused to glycoprotein D (gD) from Herpes Simplex Virus 1 (HSV-1), an immune activator of dendritic cells (DCs), leading to enhanced activation of antigen-specific T-cell responses. Mice were immunized with two doses of the electroporated DNA vaccine encoding the gD-fused polyepitope, which induced robust interferon-gamma– and tumor necrosis factor-alpha–producing T cell responses compared to control mice. In addition, K18-hACE2 transgenic mice showed protection against intranasal challenge with the original SARS-CoV-2 strain, with reduced clinical symptoms, less weight loss, and decreased viral burden in both lung and brain tissues. The results experimentally confirm the protective role of T cells in vaccine-induced protection against SARS-CoV-2 and open perspectives for the development of universal anti-coronavirus vaccines. Full article

Sindbis virus (SINV), a prototype of the Alphavirus genus (family Togaviridae), is a globally distributed arbovirus causing febrile rash and debilitating arthritis in humans. Viral structural proteins—capsid (C), E1, and E2—are fundamental to the virion’s architecture, mediating all stages from assembly to host cell entry and pathogenesis, thus representing critical targets for study. This review consolidates the historical and current understanding of SINV structural biology, tracing progress from early microscopy to recent high-resolution cryo-electron microscopy (cryo-EM) and X-ray crystallography. We detail the virion’s precise T = 4 icosahedral architecture, composed of a nucleocapsid core and an outer glycoprotein shell. Key functional roles tied to protein structure are examined: the capsid’s dual capacity as a serine protease and an RNA-packaging scaffold that interacts with the E2 cytoplasmic tail; the E1 glycoprotein’s function as a class II fusion protein driving membrane fusion; and the E2 glycoprotein’s primary role in receptor binding, which dictates cellular tropism and serves as the main antigenic target. Furthermore, we connect these molecular structures to viral evolution and disease, analyzing how genetic variation among SINV genotypes, particularly in the E2 gene, influences host adaptation, immune evasion, and the clinical expression of arthritogenic and neurovirulent disease. In conclusion, the wealth of structural data on SINV offers a powerful paradigm for understanding alphavirus biology. However, critical gaps persist, including the high-resolution visualization of dynamic conformational states during viral entry and the specific molecular determinants of chronic disease. Addressing these challenges through integrative structural and functional studies is paramount. Such knowledge will be indispensable for the rational design of next-generation antiviral therapies and broadly protective vaccines against the ongoing threat posed by SINV and related pathogenic alphaviruses. Full article

Anthrax remains a serious bioterrorism threat for which new and thermostable vaccines are needed. We previously demonstrated that immunization of rabbits with multiple-antigenic-peptide (MAP) vaccines elicit antibody (Ab) against the loop-neutralizing-determinant (LND), a cryptic linear neutralizing epitope in the 2β2-2β3 loop of protective antigen (PA) from Bacillus anthracis (B. anthracis), which mediates the complete protection of rabbits from inhalation spore challenge with B. anthracis Ames strain. Importantly, LND-specific Ab is not significantly elicited with PA-based vaccines. In the current study, we sought to identify a second unique neutralizing epitope which would also not overlap with the neutralizing specificities elicited by PA-based vaccines, and which could be combined with an LND vaccine as a prototype bivalent vaccine for anthrax. We evaluated linear peptide sequences in the α2-α3 helices of domain 3 of lethal factor (LF) in the form of virus-like particle (VLP) vaccines. Immunogenicity studies confirmed the presence of a 20-mer peptide sequence that is capable of eliciting protective levels of neutralizing Ab following two immunizations of rabbits using human-use adjuvants, and lyophilization of the VLPs did not diminish their immunogenicity. To our knowledge, this is the first demonstration that immunization with linear peptide sequences from LF can elicit protective levels of neutralizing Ab in vivo. Full article

While a global downward trend in rotavirus diarrhea cases has been observed following vaccine introduction, reassortment, genetic drift, and vaccine-escaping strains remain a concern, particularly in Sub-Saharan Africa. Here, we provide genomic insights into three equine-like G3P[8] rotavirus strains detected in Benin during the post-vaccine era. Whole-genome sequencing was performed using the Illumina MiSeq platform, and genomic analysis was conducted using bioinformatics tools. The G3 of the study strains clustered within the recently described lineage IX, alongside the human-derived equine-like strain D388. The P[8] is grouped within the lineage III, along with cognate strains from the GenBank database. Both the structural and non-structural gene segments of these study strains exhibited genetic diversity, highlighting the ongoing evolution of circulating strains. Notably, we identified a novel NSP2 lineage, designated NSP2-lineage VI. Amino acid comparisons of the G3 gene showed two conservative substitutions at positions 156 (A156V) and 260 (I260V) and one radical substitution at position 250 (K250E) relative to the prototype equine-like strain D388, the equine strain Erv105, and other non-equine-like strains. In the P[8] gene, three conservative (N195G, N195D, N113D) and one radical (D133N) substitutions were observed when compared with vaccine strains Rotarix and RotaTeq. These findings suggest continuous viral evolution, potentially driven by vaccine pressure. Ongoing genomic surveillance is essential to monitor genotype shifts as part of the efforts to evaluate the impact of emerging strains and to assess vaccine effectiveness in Sub-Saharan Africa. Full article

The 100-Day Mission, coordinated by the Coalition for Epidemic Preparedness Innovations (CEPI) and endorsed by significant international stakeholders, aims to shorten the timeframe for developing and implementing vaccines to 100 days after the report of a new pathogen. This ambitious goal is outlined as an essential first step in improving pandemic preparedness worldwide. This review highlights the mission’s implementation potential and challenges by examining it through the lens of low- and middle-income countries (LMICs), which often face barriers to equitable vaccine access. This article explores the scientific, economic, political, and social aspects that could influence the mission’s success, relying on lessons learned from previous pandemics, such as the Spanish flu, H1N1, and COVID-19. We also examined important cornerstones like prototype vaccine libraries, accelerated clinical trial preparedness, early biomarkers identification, scalable manufacturing capabilities, and rapid pathogen characterization. The review also explores the World Health Organization (WHO) Pandemic Agreement and the significance of Phase 4 surveillance in ensuring vaccine safety. We additionally evaluate societal issues that disproportionately impact LMICs, like vaccine reluctance, health literacy gaps, and digital access limitations. Without intentional attempts to incorporate under-resourced regions into global preparedness frameworks, we argue that the 100-Day Mission carries the risk of exacerbating already-existing disparities. Ultimately, our analysis emphasizes that success will not only rely on a scientific innovation but also on sustained international collaboration, transparent governance, and equitable funding that prioritizes inclusion from the beginning. Full article