Novel duck reovirus (NDRV) causes high morbidity in ducklings, and the recovered individuals often show stunted growth. There is currently no commercial vaccine available for effectively controlling NDRV. The capsid protein σC in NDRV is responsible for virus–cell attachment and thus plays a key role in viral infection. In this study, we aimed to develop a new vaccine candidate presenting σC on the virus-like particle AP205 according to specific binding with SpyCatcher and SpyTag. Firstly, σC-SpyTag was expressed in E. coli and purified, which was then coupled to AP205-SpyCatcher to generate AP205-σC. Then, AP205-σC was characterized, and the results demonstrated that it remained intact and had a homogenous viral particle structure, which packaged prokaryotic ssRNA inside. After immunizing ducklings with it, AP205-σC induced σC-specific IgY antibodies that could effectively recognize NDRV. Importantly, these antibodies were able to block the virus from infecting duck embryo fibroblasts in vitro, suggesting the vaccine successfully elicited neutralizing antibodies in ducklings. Consistently, the clinical pathologic features like lesions or listlessness in the AP205-σC-immunized ducklings were drastically reduced compared to those in the control group. Moreover, the viral loads in the AP205-σC-immunized ducklings were strikingly reduced, indicating that the vaccine contributed to viral clearance. These results suggested that AP205-σC exhibited excellent immunogenicity and posed protection against NDRV infection in ducks. In conclusion, AP205-σC has the potential to induce neutralizing antibody responses against NDRV and is worthwhile to develop for large-scale application.

Zein has been used in pharmaceutical applications, including the synthesis of nanoparticles applied as delivery systems for drugs and antigens. Zein nanoparticles (ZNPs) are classified as organic nanoparticles withdesirable characteristics, such as safety, biodegradability, low toxicity, and high loading capacity. The aim of this work was to obtain ZNPs by a simple and low-cost method and assess their potential as nanocarriers for the delivery of antigens, enhancing immunogenicity. ZNPs were produced by the nanoprecipitation method, showing a mean hydrodynamic size of 220 nm, a low polydispersity index (0.13± 0.15), and negative zeta potential (-8.9 ± 0.89). The adsorption-mediated antigen loading capacity of the obtained ZNPs was assessed using bovine serum albumin (BSA) as a model antigen. Different mass ratios of ZNPs: BSA were evaluated in the absorption experiments (1:0.5, 1:1, and 1:2), and samples were analyzed by TEM to determine size and particle morphology. The best adsorption efficacy was observed at a 1:2 mass ratio, with 63% efficacy, and a two-fold increase in particle size wasobserved upon BSA adsorption (424nm ± 36). To improve BSA adsorption, different adsorption buffers (Tris or Citrate buffer) at different pH values (5.5 or 7.4) were tested. The adsorption was improved using a Tris buffer at pH 5.5 during the adsorption step, while storage was set by using a Tris buffer at pH 7.4. In conclusion, a simple method to produce monodisperse ZNPs and bioconjugates based on such carriers was achieved, and its application in developing vaccine prototypes is guaranteed.

Pre-existing dengue virus (DenV) immunity is a risk factor for severe dengue mediated by antibody-dependent enhancement (ADE), which occurs when a seropositive DenV patient is re-infected with a DenV of a different serotype. DenV and Zika virus (ZikV) are highly similar, and ADE has been observed between them. As DenV and ZikV co-circulate in many regions of the world, a vaccine that provides protection against both viruses without inducing ADE is needed. The main objective of this work was to determine the potential as a vaccine candidate of a mimotope of the shared epitope EDE of DenV and ZikV, displayed in the capsid of adeno-associated virus serotype 8 (AAV-8).

AAV-8 capsids that display the EDE mimotope (chimeric VLP) and native control capsids (native VLP) were produced. The VLPs were purified using iodixanol gradients and characterized by Western blot, dot blot, transmission electron microscopy, and cryo-electron microscopy, showing that the chimeric VLPs were recognized by a monoclonal antibody specific for DenV and ZikV, and not for AAV-8, and that the chimeric protein assembled into AAV-8 capsids with typical morphologies. Groups of BALB/c mice were subcutaneously or intramuscularly immunized with chimeric VLP, native VLP, or controls. Serum samples were collected to evaluate the humoral immune response through the ELISA test. Mice immunized with chimeric VLP produced antibodies that recognized DenV serotype 2 and ZikV. In silico biophysical studies were performed to analyze the interaction between the mimotope and the antibody against DenV and ZikV. We then evaluated the function of the chimeric VLP as a viral vector. The chimeric VLP could encapsidate the eGFP gene and transduce the HEK-293 and CHO cells, showing that the function of the AAV vector was retained after modification.

This work represents a new strategy for the development of a vaccine against DenV and ZikV based on a mimotope.

TIGIT, a T-cell immunoreceptor with Ig and ITIM domains, has been recognized as a critical inhibitory receptor on T cells and natural killer (NK) cells. It plays an important role in immune suppression mediated by tumors. Tumor cells express CD155, which engages TIGIT and hampers T cell or NK cell activation to perform cytotoxicity, thus facilitating tumor progression. Releasing TIGIT on immune cells from CD155 binding to target tumor cells is one promising strategy for cancer immunotherapy. To this end, TIGIT-specific nanobodies were generated by immunizing camels with the TIGIT protein, from which a library of nanobodies was built. Then, Monoclonal nanobodies were screened by phage display, and high-affinity nanobodies for TIGIT were identified. Competitive ELISA assays were performed to demonstrate that nanobodies effectively inhibited the binding of TIGIT to CD155. Furthermore, the cytotoxicity activities of NK-92MI cells were significantly enhanced by adding TIGIT antibodies; meanwhile, higher cell degranulation was determined. At the same time, the viability of tumor cells after mixing with NK-92MI cells was detected, showing that the viabilities of K562 cells were as high as 90%, suggesting the limited cytotoxicity of NK-92MI cells. In contrast, the viabilities of K562 cells were significantly reduced when the nanobodies were added, indicating that nanobodies effectively block TIGIT on NK cells from binding to CD155 on tumor cells. These findings suggest that the screened nanobodies have promising potential for further evaluation in tumor-bearing mouse models. These nanobodies might offer significant benefits in clinical settings by improving patient selection and therapeutic outcomes in cancer immunotherapy.

Influenza vaccination faces challenges due to viral mutagenicity, necessitating a shift towards universal vaccine approaches. Many current vaccinations target the globular head region of the hemagglutinin (HA) surface protein of the Influenza virus. However, despite the widespread use of this technique, it does not offer broad protection against possible mutations or variations that naturally occur in the Influenza virus. Our study focuses on creating a broadly effective influenza vaccine by targeting the conserved hemagglutinin stem using virus-like particles (VLPs). Through innovative Spy Catcher/Spy Tag technology, we engineered VLPs presenting the HA stem on their surface adjuvanted with the VLP composition containing the Hepatitis B core protein and Flagellin, enhancing immunogenicity. The virus-like particle is made up of two components. The first component is the core of the particle, in which the HBc-flagellin particle assembles into a spherical particle, displaying the Spy Catcher protein on the surface of this particle. This is then combined in solution with a custom HA stem peptide, conjugated with Spy Tag to complete the VLP, with the HA stem displayed on the surface. Preliminary results demonstrating the successful assembly of VLPs into spherical particles visualized by transmission electron microscopyproved the remaining ability of Spy Tag binding to the virus core, and completed gene cloning for the HA stem protein. This project offers insights into universal vaccine design and holds promise for advancing influenza prevention strategies, as well as a theoretical platform for other virus-like particle vaccines.

Introduction: The Covid-19 pandemic has had huge effects on the physical life and psychological health of people worldwide. Not only have adults been affected, but children and adolescents have also suffered. The hope of a return to normal life was raised with the development of vaccines, but misinformation and insufficient knowledge of authentic science about the effectiveness and safety of the vaccines have created another psychological phenomenon, namely, anxiety over the vaccinations themselves. Children are more likely to be affected by such fears and anxieties. To address this problem, a unique scale was developed to measure anxiety among teenagers regarding Covid-19 vaccines, and the scale’s psychometrics (validity and reliability) were evaluated.

Methods: The Scale items were developed, and after arriving at 30 total items, item pooling and division of the items into five subscales was performed. These subscales measure Emotional, Cognitive, Physiological, Behavioral, and Emotion Regulation dimensions. Data was collected from 1296 participants with an age range of 12--18. To check the psychometrics of the scale, Exploratory Factor Analysis, Variance, Rotated Factor Matrix, Construct Reliability and Validity, and Confirmatory Factor Analysis were performed.

Results: For the five dimensions that were developed, the Cronbach's alpha reliability coefficients were as follows: Emotional Dimension, 0.797; Cognitive Dimension, 0.857; Physiological Dimension, 0.951; Behavioral Dimension, 0.769; and Emotion Regulation, 0.900.

Conclusions: The developed scale is reliable and valid for measuring vaccination anxiety among teens. Future research should follow up on this study with a more expansive population worldwide.

DNA vaccines have been developed against viruses for many years. For COVID-19, acid nucleic immunization has been evaluated. A few preclinical studies have shown that the combination of the spike and nucleocapsid proteins of SARS-CoV-2 induced a robust immune response. In this work, we designed a plasmid that codifies for fusion proteins and evaluated its ability to elicit an immune response in a mouse model. Using in silico approaches, we determined the most immunogenic regions of the spike (S) and nucleocapsid (N) proteins of the SARS-CoV-2 Omicron strain. Once the sequences were selected, we generated the structure of this fusion protein in AlphaFold and determined its physicochemical and immunogenic properties on several platforms. The sequence was cloned in pcDNA3.1 and named pcDNA3.1/O-SN. The expression of plasmid was evaluated by Western blot and immunofluorescence. Then, BALB /c mice were immunized with 25 µg of pcDNA3.1/O-SN and parental vector pcDNA3.1. Three doses at 20-day intervals were administrated. After immunization, bleedings were performed, serum samples were obtained, and the humoral response was determined. Splenocytes were obtained from the immunized mice, and the cellular T-cell response was analyzed by flow cytometry. Finally, a cross-reaction with RBD from different SARS-CoV-2 variants of concern was evaluated. Specific antibody responses of IgM and IgG against N and S1 proteins from SARS-CoV-2 were observed in pcDNA3.1/O-SN-immunized mice. Furthermore, these antibodies exhibited neutralization activity, and production of IFN-γ was detected in CD4+ and CD8+ cells from the pcDNA3.1/O-SN-immunized mice. Additionally, a sera cross-reaction was observed with different VOCs. Our results indicate that DNA vaccination with the pcDNA3.1/O-SN generated by our working group is capable of inducing a specific humoral and cellular immune response.

SARS-CoV-2 has spread worldwide since 2019, causing the devastating COVID-19 pandemic. As of June 23, 2024, the cumulative number of infections worldwide has exceeded 705 million. As the structural protein of SARS-CoV-2, nucleocapsid (N) protein plays a key role in the viral lifecycle and participates in various activities during virus invasion, including interaction with the host immune system. In this study, we used computational methods to predict the MHC-I dominant epitopes, which brought about 282 dominant epitopes restricted to the human HLA-I superfamilies and mouse H-2 haplotypes. Further analysis of immunogenicity and conservation yielded the “preferred epitopes”. Among them, KTFPPTEPK, LSPRWYFYY, SPRWYFYYT and NTASWFTAL have been validated by other laboratories in one or two dimensions in terms of their antigenic profiles. Through our multi-disciplinary research, we also screened out and obtained four unproven “preferred epitopes”. Docking simulations were conducted with the corresponding MHC-I alleles. Then, two-way hierarchical clustering revealed the principles on immunoreacitivities between NP peptides and pan-MHC-I haplotypes. We propose a state-of-the-art epitope exploitation strategy that integrates multiple tools and approaches and provides prospects for the development and application of epitope-based immunotherapy in viral epidemics. Our study also provides insight into extensive protective mechanisms between different variants, providing guidance for the development of highly protected epitope vaccines in the future.

Triple-Negative Breast Cancer (TNBC) represents a formidable subtype of breast cancer, characterized by the absence of estrogen receptors, progesterone receptors, and HER2 protein. This phenotype presents significant treatment challenges due to its aggressive nature and lack of targeted therapies. Consequently, there has been an intensified focus on novel therapeutic strategies, including vaccination approaches, which hold promise in eliciting robust anti-tumor immune responses. This review provides a comprehensive analysis of current vaccination strategies employed in the management of TNBC. It explores various vaccine platforms, such as peptide-based, dendritic cell-based, viral vector-based, and virus-like nanoparticle (VLP)-based vaccines, highlighting their mechanisms of action. Furthermore, this review examines the role of neoantigen vaccines, which leverage tumor-specific mutations to enhance immune specificity and efficacy, and combination strategies that integrate vaccines with other modalities, including immune checkpoint inhibitors and conventional chemotherapies, to potentiate anti-tumor responses and overcome immunosuppressive tumor microenvironments. Emerging trends, such as personalized vaccination approaches tailored to individual patient tumor profiles, are evaluated for their potential to revolutionize TNBC treatment paradigms. Additionally, we address the challenges and limitations faced in vaccine development, including antigen selection, delivery methods, and the heterogeneity of TNBC. This review concludes with future perspectives on optimizing vaccine-based therapies and their integration into standard TNBC treatment regimens. By synthesizing current research and clinical advancements, this review aims to provide a detailed understanding of vaccination strategies in TNBC, underscoring their potential to improve patient outcomes and contribute to the ongoing battle against this aggressive cancer subtype.

Background: Respiratory syncytial virus (RSV) is a major pathogen that causes respiratory illness in adults and most commonly affects populations with additional comorbidities or the elderly. RSV poses a significant risk for severe respiratory infections among adults. The mRNA-1345 vaccine utilizes advanced mRNA technology. While mRNA vaccines have demonstrated considerable success in other infectious disease contexts, detailed evidence on the efficacy, safety, and immunogenicity of mRNA-1345 specifically for RSV among adults remains scarce. Objective: We aimed to evaluate the effectiveness and safety profile of the mRNA-1345 vaccine in preventing RSV infections in adult populations. Method: A search was conducted through PubMed and the Cochrane Library to identify randomized controlled trials examining the efficacy and safety of the mRNA-1345 vaccine against RSV. The review was conducted adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: The mRNA-1345 vaccine demonstrated an overall efficacy of 68.4% against RSV- associated respiratory illness (ARI) and 83.7% against RSV-associated lower-respiratory-tract disease (LRTD) with at least two signs or symptoms in individuals aged 60 and older. Concerning RSV-associated respiratory illness (ARI), the vaccine provided 78.5% protection against RSV-A and 51.7% against RSV-B strains. The vaccine's safety profile was comparable to a placebo, with mild to moderate adverse events like injection-site pain and fever. Adverse events were rare and equally distributed between the vaccine and placebo groups. Conclusion: The mRNA-1345 vaccine has demonstrated significant benefits in preventing RSV-associated LRTD and ARI in adults aged 60 and older. Additionally, it has proven to have an acceptable safety profile across age groups, particularly in those aged 18-49 and 60 and above. The vaccine also elicited a robust immune response, with clear evidence of immunogenicity. Overall, the mRNA-1345 vaccine emerges as a promising candidate for adult vaccination.