Vaccine Preparation Research Articles

VIABILITY OF ORTHOPOXVIRUS STRAINS IN THE SELECTION OF A STABILIZER FOR LYOPHILIZATION, STORAGE AND TRANSPORTATION

The article presents the results of research on the choice of a stabilizer for strains "CP-65K" and "BIEMG-51" orthopoxviruses, which helps to preserve their biological activity during lyophilization, storage in various temperature and time conditions and transportation. To select a stabilizing medium that ensures the greatest preservation of the virus during lyophilization and subsequent storage, depending on the composition of protective media, temperature and shelf life, we prepared 3 samples of each vaccine preparation with stabilizing additives: I and V samples consisted of 5 % peptone and 3 % sucrose; II and VI samples - of 3 % peptone and 2 % sucrose; III and VII samples - from skimmed milk; IV and VIII samples - control. All protective media were added to the viral materials in a 1:1 ratio. As a result of the conducted studies, it was found that of the tested samples of stabilizing media, the most protective property for the strains «CP-65K» CPOX and "BIEMG-51" smallpox vaccine virus had a stabilizing medium consisting of a mixture of peptone (5 %) and sucrose (3 %) in the final concentration, which ensured the safety of vaccine strains for 12 months month. at a temperature of (2-8) °C and minus (40.0±1.0) °C without a significant decrease in their biological activity (6.50±0.14 lg TCID50/cm3 and 6.25±0.14 lg TCID50/cm3, respectively).

Anti-cancer immune effect of human colorectal cancer neoantigen peptide based on MHC class I molecular affinity screening

BackgroundTumor antigen peptide vaccines have shown remarkable efficacy, safety, and reliability in recent studies. However, the screening process for immunopotent antigenic peptides is cumbersome, limiting their widespread application. Identifying neoantigen peptides that can effectively trigger an immune response is crucial for personalized cancer treatment.MethodsWhole exome sequencing was performed on patient-derived colon cancer cells to predict 9-amino-acid (9aa) neoantigen peptides. In vitro simulation of endogenous antigen presentation by antigen-presenting cells (dendritic cells) to CD8+ T cells was conducted, aiming to activate the CD8+ immune response to the predicted antigens. The immunological effects of each neoantigen were assessed using flow cytometry and ELISpot assays, while the relationship between neoantigen immunogenicity and MHC molecular affinity was examined.Results1. Next-generation sequencing (NGS) predicted 9-amino acid (9aa) neoantigen peptides for subsequent immunological analysis.2. Higher mDC Levels in Experimental Group: CD11c+CD83+ mature dendritic cells (mDCs) were 96.6% in the experimental group, compared to 0.051% in the control group. CD80 fluorescence intensity was also significantly higher in the experimental group, confirming a greater mDC presence.3. Neoantigen Peptides Promote CD4+, CD8+ T, and NK Cell Proliferation: After 14 days, flow cytometry showed higher percentages of CD4+ T (37.41% vs 7.8%), CD8+ T (16.67% vs 14.63%), and NK cells (33.09% vs 7.81%) in the experimental group, indicating that the neoantigen peptides induced proliferation of CD4+, CD8+ T cells, and NK cells. 4. The results, analyzed using two-way ANOVA, showed that the standardized T-value for HLA molecular affinity variation in the 1-4 range (Group B) was significantly higher than for ≤1 (Group A, p < 0.0001) and >4 (Group C, p < 0.05). Regarding HLA-allele genotypes, HLA-Type 1 had a significantly higher standardized T-value than HLA-Type 2 (p < 0.05) and HLA-Type 3 (p < 0.0001). HLA-Type 1 was identified as the allele associated with the highest T-value.Conclusion1. The most immunogenic neoantigens typically exhibit an MHC molecular affinity variation between 1 and 4, indicating that stronger immunogenicity correlates with higher MHC molecular affinity variation. 2. Each patient's HLA molecules were classified into Types 1, 2, and 3, with Type 1 showing the highest binding capacity for neoantigens. Our findings indicate that the most immunogenic neoantigens were associated with HLA Type 1. 3. Neoantigen peptides were shown to activate the proliferation of both CD8+ T-cells and induce proliferation of CD4+ T-cells and NK cells. 4. Variation in MHC molecular affinity and HLA neoantigen genotype are anticipated to serve as valuable variables for screening highly immunogenic neoantigens, facilitating more efficient preparation of effective polypeptide tumor vaccines.

Pangenome – its Aspect and Prospect

Pangenome is a very new discipline showing a collection of unique and variable genomes of any species in one model. This discipline is a combination of three subjects of Biology like Computer Science and Applied Mathematics. All genes from all species or strains are called Pangenomes. Pangenome was first discovered during the preparation of protein-based vaccine of the G group of Streptococcus sp. which is the main cause of neonatal life-threatening disease by a team of scientists led by Tettelin. Conventional method of Vaccine preparation was not successful due to the existence of five different serotypes in this organism. Then Tettelin with groups of scientists tried to use the genome sequence information for preparing protein- based vaccine in G group of Streptococcus. During their studies, two gap free genomes were found in this G group of bacteria. After sequencing studies of many strains, they found several regions of diversity (genomic diversity) among different isolates of same strain. After sequencing a large number of genomes, they realized that genes belong to isolates present in the species but not present in genomes. Then the Pangenome concept came to their mind and genes were classified into Core genome, Accessory or Dispensable genome and Species-specific genomes. Bacteria genomes have a distinct number of genes but there are differences in the genomes of different strains of a single species that is mainly due to horizontal gene transfer of genes from other bacteria. The Pangenome concept and its discovery was discussed. Plant genomes are dynamic with whole genome duplication, tandem duplication, transposable element duplication, chromosomal rearrangements or structural variations like deletion, inversion, translocation and recombination between species. Several methods have already been tried for the improvement of crop plants like Marker Assisted Selection (MAS), QTL mapping, Single Nucleotide Polymorphisms (SNP), Copy number variations and Genome Wide Association Studies (GWAS) by comparing with Reference Genome Assemblies representing the genome sequence of the genome of an individual or organism. But the Reference genome is not able to locate all genetic variations of a species. To overcome this limitation the concept of Pangenomes may help in the crop improvement which has been discussed. Pangenomic studies have already been done in many crop plants like Rice, Wheat, Maize, Brassica, Soybean etc. Some of all these aspects have been discussed.

Attenuated African swine fever viruses and the live vaccine candidates: a comprehensive review.

The African swine fever virus (ASFV) is spreading worldwide and causing huge economic losses to the global pig industry. The ASFV genome is 170-193 kb in length, contains approximately 150 open reading frames, and encodes more than 200 proteins, most of which have unknown functions. Owing to the unique viral structure, replication strategy, large number of genes of unknown function, and complicated pathogenesis, vaccine development research is challenging. Several naturally attenuated ASFV isolates have been extensively investigated and many genetically manipulated, gene-deleted, and cell-adapted ASFVs have been reported. Currently, live attenuated viruses prepared from weakly virulent strains are an efficient method to provide effective protection in vaccinated pigs; however, these have seldom been widely approved for vaccine use, except in Vietnam. Herein, we summarize the attenuated isolates or vaccine candidates for live vaccines derived from different sources, including naturally mutated, attenuated, cell-adapted, and genetically modified recombinant ASFVs. This will help to understand the gene function and immunogenicity of attenuated live ASFV, as well as the shortcomings of these viruses as vaccine candidates, and provide clues to prepare live, efficient, and safe vaccines for African swine fever.IMPORTANCEOutbreaks of African swine fever (ASF) have caused devastating losses to the global pig industry. Pigs immunized with ASFV attenuated virus can resist the lethal challenge of a strongly virulent virus. Here, we summarize the virulence of naturally mutated, cell-adapted, and genetically recombinant ASFV for pigs, and the protective effect after facing an attack challenge. We also analyze the advantages and disadvantages of ASFV attenuated viruses as vaccine candidates to provide clues for the preparation of efficient and safe live African swine fever vaccines.

Harnessing Bacterial Membrane Components for Tumor Vaccines: Strategies and Perspectives.

Tumor vaccines stand at the vanguard of tumor immunotherapy, demonstrating significant potential and promise in recent years. While tumor vaccines have achieved breakthroughs in the treatment of cancer, they still encounter numerous challenges, including improving the immunogenicity of vaccines and expanding the scope of vaccine application. As natural immune activators, bacterial components offer inherent advantages in tumor vaccines. Bacterial membrane components, with their safer profile, easy extraction, purification, and engineering, along with their diverse array of immune components, activate the immune system and improve tumor vaccine efficacy. This review systematically summarizes the mechanism of action and therapeutic effects of bacterial membranes and its derivatives (including bacterial membrane vesicles and hybrid membrane biomaterials) in tumor vaccines. Subsequently, the authors delve into the preparation and advantages of tumor vaccines based on bacterial membranes and hybrid membrane biomaterials. Following this, the immune effects of tumor vaccines based on bacterial outer membrane vesicles are elucidated, and their mechanisms are explained. Moreover, their advantages in tumor combination therapy are analyzed. Last, the challenges and trends in this field are discussed. This comprehensive analysis aims to offer a more informed reference and scientific foundation for the design and implementation of bacterial membrane-based tumor vaccines.

Replication of the Venezuelan Equine Encephalitis Vaccine from a Synthetic PCR Fragment.

There is no approved human vaccine for Venezuelan equine encephalitis (VEE), a life-threatening disease caused by the VEE virus (VEEV). In previous studies, plasmid DNA encoding the full-length RNA genome of the VEE V4020 vaccine was used for the preparation of experimental live virus VEE vaccines in the plasmid-transfected cell culture. Here, we used the high-fidelity polymerase chain reaction (PCR) to prepare synthetic, transcriptionally active PCR (TAP) fragments encoding the V4020 genome. TAP fragment initiated the replication of the V4020 live virus vaccine in TAP fragment-transfected cells. A transfection of less than 1 ug of TAP fragment resulted in the replication of the V4020 vaccine virus in CHO cells. We conclude that not only plasmid DNA but also synthetic PCR-generated DNA fragments can be used for the manufacturing of live vaccines for VEEV and, potentially, other viruses.

Physical and Chemical Inactivators Evaluation for the Puumala Virus Vaccine Technology Development

Relevance. Hemorrhagic fever with renal syndrome (HFRS) is leading among natural focal human diseases in Russia, the causative agents of which - orthohantaviruses - belong to the order Bunyavirales, family Hantaviridae. More than 98% of HFRS cases in Russia are caused by the Puumala virus. It is a serious zoonosis for which there is still no specific treatment. The WHO has not approved a vaccine. The aim of this study was to investigate the effect of formaldehyde, β-propiolactone, hydrogen peroxide, ultraviolet rays, gamma irradiation and thermal inactivation on the immunogenic activity of inactivated vaccine preparations against HFRS Materials and methods. To achieve this aim, experimental vaccine preparations based on the PUU-TKD/VERO strain of Puumala virus were prepared and inactivated using the methods described above. The time intervals required for complete inactivation of the virus were determined, and the effects of the inactivators on viral RNA and immunogenic activity of the vaccine preparations were evaluated in BALB/c mouse and Syrian hamster models. Results. According to our results, vaccine preparations inactivated by different chemical and physical methods, which differ significantly in the mechanism of the mechanism of interaction with the virus, show no significant differences in immunogenic activity, except for thermal inactivation. Conclusion. A certain advantage of β-propiolactone is the short virus inactivation time, its complete degradation into non-toxic compounds within a few hours, and the reduction of total protein content after sterilization filtration, which is probably due to less aggregation of virus particles and cellular proteins

Preparation of Vaccine from Biofilm Proteins of Staphylococcus aureus and Incorporate it in Liposomes for Induction of CXCL-5 Production in Albino Rats

Preparation of Vaccine from Biofilm Proteins of Staphylococcus aureus and Incorporate it in Liposomes for Induction of CXCL-5 Production in Albino Rats

Enhancing NA immunogenicity through novel VLP designs.

Current influenza virus vaccines poorly display key neuraminidase (NA) epitopes and do not robustly induce NA-reactive antibodies; instead, they focus on the induction of hemagglutinin (HA)-reactive antibodies. Next-generation influenza vaccines should be optimized in order to activate NA-reactive B cells and to induce a broadly cross-reactive and protective antibody response. We aimed at enhancing the immunogenicity of the NA on vaccines by two strategies: (i) modifying the HA:NA ratio of the vaccine preparation and (ii) exposing epitopes on the lateral surface or beneath the head of the NA by extending the NA stalk. The H1N1 glycoproteins from the influenza virus A/California/04/2009 strain were displayed on human immunodeficiency virus 1 (HIV-1) gag-based virus-like particles (VLP). Using the baculovirus insect cell expression system, we biased the quantity of surface glycoproteins employing two different promoters, the very late baculovirus p10 promoter and the early and late gp64 promoter. This led to a 1:1 to 2:1 HA:NA ratio, which was approximately double or triple the amount of NA as present on the wild-type influenza A virus (HA:NA ratio 3:1 to 5:1). Furthermore, by insertion of 15 amino acids from the A-New York/61/2012 strain (NY12) which prolongates the NA stalk (NA long stalk; NA-LS), we intended to improve the accessibility of the NA. Six different types of VLPs were produced and purified using a platform downstream process based on Capto-Core 700™ followed by Capto-Heparin™ affinity chromatography combined with ultracentrifugation. These VLPs were then tested in a mouse model. Robust titers of antibodies that inhibit the neuraminidase activity were elicited even after vaccination with two low doses (0.3 μg) of the H1N1 VLPs without compromising the anti-HA responses. In conclusion, our results demonstrate the feasibility of the two developed strategies to retain HA immunogenicity and improve NA immunogenicity as a future influenza vaccine candidate.

Designing a Candidate Multi-Epitope Vaccine against Transmissible Gastroenteritis Virus Based on Immunoinformatic and Molecular Dynamics.

Transmissible gastroenteritis virus (TGEV) is an etiological agent of enteric disease that results in high mortality rates in piglets. The economic impact of the virus is considerable, causing significant losses to the pig industry. The development of an efficacious subunit vaccine to provide promising protection against TGEV is of the utmost importance. The viral antigen, spike glycoprotein (S), is widely regarded as one of the most effective antigenic components for vaccine research. In this study, we employed immunoinformatics and molecular dynamics approaches to develop an 'ideal' multi-epitope vaccine. Firstly, the dominant, non-toxic, highly antigenic T (Th, CTL) and B cell epitopes predicted from the TGEV S protein were artificially engineered in tandem to design candidate subunit vaccines. Molecular docking and dynamic simulation results demonstrate that it exhibits robust interactions with toll-like receptor 4 (TLR4). Of particular significance was the finding that the vaccine was capable of triggering an immune response in mammals, as evidenced by the immune simulation results. The humoral aspect is typified by elevated levels of IgG and IgM, whereas the cellular immune aspect is capable of eliciting the robust production of interleukins and cytokines (IFN-γ and IL-2). Furthermore, the adoption of E. coli expression systems for the preparation of vaccines will also result in cost savings. This study offers logical guidelines for the development of a secure and efficacious subunit vaccine against TGEV, in addition to providing a novel theoretical foundation and strategy to prevent associated CoV infections.

New vaccination approach using formalin-killed Streptococcus pyogenes vaccine on the liver of Oreochromis niloticus fingerlings

Newly synthesized vaccines prepared from formalin-killed bacteria Streptococcus pyogenes were investigated in the current study to evaluate the effectiveness of the newly synthesized vaccine as well as their safety by injected intraperitoneal. The study involved several steps 1st step is the preparation of the vaccine followed by the 2nd step: Evaluate the effectiveness and vaccine safety against pathogenic S. pyogenes through 4 different groups including control (Group I). Group II (Bacterial, infected group), Group III (Vaccine), and the Last group was the challenged group after the vaccination (Vacc + Bac). Different Immunological and biochemical parameters were measured in addition to hematological and histopathological examinations. For example, oxidative/antioxidants, inflammatory biomarkers, fragmentation and cell damage, and finally the histopathological study. The current study showed an increase in all oxidative, inflammatory, and cell damage (DNA fragmentation assays), additionally markedly elevation in histopathological cell damage in the infected group (Group II) compared with the control group. The vaccine and challenged after vaccination group (vaccine + Bacteria), showed great improvement in oxidative biomarkers (LPO) and an increase in antioxidants biomarkers (GSH, SOD, GST, DPPH, ABTS, GR and GPx), Also the inflammation and histopathological examination. The newly synthesized vaccine improved the resistance of Oreochromis niloticus and can be used as a preventive therapy agent for pathogenic bacteria S. pyogenes.

Conserved linear B-cell peptides among the influenza A viral neuraminidases enhance the cross-protective potential of inactivated whole-virion influenza vaccine

Introduction. Influenza is a disease caused by a widespread virus with pandemic potential. Frequently, individuals vaccinated against seasonal influenza virus are still susceptible to the disease, indicating the need to improve the immunogenic potential of existing vaccines. To assess the efficacy of influenza virus vaccines, immune response only to a single viral antigen — hemagglutinin molecule, is taken into consideration. However, according to preclinical and clinical studies, neuraminidase (NA) stimulates cross-protective immunity, which is effective against not only homologous but also drifted variants of influenza A virus. Materials and methods. In the present study, we investigated the ability of previously selected conserved linear B-cell NA epitopes (SGYSGK, SWPDGK, EECSCYPK, VELIRGRK) to enhance the immunogenicity of an inactivated whole-virion influenza vaccine based on the model strain PR8 (iPR8). BALB/c mice were injected with iPR8 in combination with one of the peptides intramuscularly three times at two-week intervals. Blood samples were collected 14 days after the last immunization, after which the mice were challenged with heterosubtypic influenza viruses H1N1pdm09 and H3N2. Results. All immunized mice showed induction of H1N1 (PR8)-specific IgG antibodies two weeks after the third immunization. The group of mice immunized with the iPR8 vaccine preparation in combination with VELIRGRK peptide showed the most pronounced induction of IgG antibodies to the H6N1 reassortant strain, the NA of which corresponds to the iPR8 virus, indicating the ability of the NA peptide to stimulate the production of NA-specific antibodies. However, the antibodies produced after immunization were not capable to inhibit the NA enzymatic activity. Despite this, mice immunized with iPR8 in combination with anti-NA peptides showed a higher survival rate after infection with heterologous virulent influenza viruses: A/California/07/09 (H1N1pdm09) and A/Philippines/2/82 (H3N2) compared to the PBS and iPR8 groups. Conclusion. Thus, the study demonstrated the immune-potentiating effect of individual peptides corresponding to conservative linear epitopes of the NA molecule in combination with a standard inactivated influenza vaccine, which made it possible to improve the protective effect of the vaccine against heterosubtypic influenza viruses.

A nanoparticle vaccine based on the VP121–26 and VP2 structural proteins of Senecavirus A induces robust protective immune responses

Senecavirus A (SVA) is a causative agent that can cause vesicular disease in swine, which causes a great threat to the swine husbandry in the world. Therefore, it is necessary to develop a vaccine that can effectively prevent the spread of SVA. In this study, we developed a 24-polymeric nano-scaffold using β-annulus peptide from tomato bushy effect virus (TBSV) by coupling this antigen to SVA B cell epitope VP121–26 and VP2 proteins via linkers, respectively. The SVA-based nanoparticle protein of the VP1(B)-β-VP2 was expressed and purified by low-cost prokaryotic system to prepare a SVA nanoparticle vaccine. The immunological protective effect of SVA nanoparticle vaccine was evaluated in mouse and swine models, respectively. The results suggested that both mice and swine could induce high levels SVA neutralizing antibodies and IgG antibodies after two doses immunization. In addition, the swine challenge protection experiment showed that the protection rate of immune SVA nanoparticle vaccine and SVA inactivated vaccine both were 80 %, while the negative control had no protection effect. It demonstrated that SVA nanoparticle vaccine effectively prevented SVA infection in swine. In summary, the preparation of SVA vaccine by using β-annulus peptide is a promising candidate vaccine for prevent SVA transmission, and provides a new idea for the development of novel SVA vaccines.

Blockchain platform for prophylactic vaccine preparation using signature based secured authentication

Blockchain platform for prophylactic vaccine preparation using signature based secured authentication

Convergent Synthesis of a Group B Streptococcus Type III Epitope Toward a Semisynthetic Carbohydrate-Based Vaccine.

In this work, we synthesized an hexasaccharide derived from the capsular polysaccharide of group B Streptococcus type III capsular polysaccharide. Our convergent 3 + 3 strategy avoided the use of benzyl protecting groups allowing the installation of an azide anchoring group and providing a high yield for the final deprotection steps. Moreover, the minimal hexasaccharidic epitope was conjugated to CRM197 and BSA via copper-catalyzed azide-alkyne cycloaddition for the preparation of a semisynthetic carbohydrate-based vaccine.

Spatial Engineering of Heterotypic Antigens on a DNA Framework for the Preparation of Mosaic Nanoparticle Vaccines with Enhanced Immune Activation against SARS‐CoV‐2 Variants

Spatial Engineering of Heterotypic Antigens on a DNA Framework for the Preparation of Mosaic Nanoparticle Vaccines with Enhanced Immune Activation against SARS‐CoV‐2 Variants

Preparation and immunological activity evaluation of an intranasal protein subunit vaccine against ancestral and mutant SARS-CoV-2 with curdlan sulfate/O-linked quaternized chitosan nanoparticles as carrier and adjuvant

Chitosan and its derivatives are ideal nasal vaccine adjuvant to deliver antigens to immune cells. Previously, we successfully used a chitosan derivative, O-(2-Hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (O-HTCC), and a β-glucan derivative, curdlan sulfate (CS), to prepare a nanoparticle adjuvant CS/O-HTCC which could deliver ovalbumin to antigen presenting cells (APCs) through nasal inhalation. In this article, we used SARS-CoV-2 spike receptor binding domain (S-RBD) as the antigen and CS/O-HTCC nanoparticles as the adjuvant to develop a nasal mucosal protein subunit vaccine, CS/S-RBD/O-HTCC. The humoral immunity, cell-mediated immunity and mucosal immunity induced by vaccines were evaluated. The results showed that CS/S-RBD/O-HTCC could induce desirable immunization with single or bivalent antigen through nasal inoculation, giving one booster vaccination with mutated S-RBD (beta) could bring about a broad cross reaction with ancestral and different mutated S-RBD, and vaccination of the BALB/c mice with CS/S-RBD/O-HTCC containing S-RBD mix antigens (ancestral and omicron) could induce the production of binding and neutralizing antibodies against both of the two antigens. Our results indicate that CS/O-HTCC is a promising nasal mucosal adjuvant to prepare protein subunit vaccine for both primary and booster immunization, and the adjuvant is suitable for loading more than one antigen for preparing multivalent vaccines.

Covid-19 vaccine hesitancy and its predictors among diabetic patients on follow-up at public hospitals in Nekemte Town, Western Ethiopia.

Understanding and addressing the concerns of vaccine-hesitant individuals, including those with chronic diseases, is key to increasing vaccine acceptance and uptake. However, in Ethiopia, there is limited evidence on the COVID-19 vaccine hesitancy and predictor variables among diabetic patients. Hence, the study aimed to assess Covid-19 Vaccine Hesitancy and Predictor variables among Diabetic Patients on Follow-Up at Public Hospitals in Nekemte Town, Western Ethiopia. Facility based cross sectional study was conducted among 422 diabetic patients attending public hospitals at Nekemte Town, Western Ethiopia between January, to February, 2023. Study participants were recruited by systematic random sampling. The data were collected interviewee administered pre-tested structured survey questioner. The collected data were entered and cleaned using Epi-Data software 4.6 version. The cleaned data were analyzed using SPSS. 25.0 Statical software. Descriptive statistics like frequency, mean and percentage, and binary logistic regression was applied to identify independent predictors of Covid-19 vaccine hesitancy and association between variables were declared at p-value of 0.05. The overall magnitude of COVID-19 vaccine hesitancy was 15.2% (95% CI: 11.6-18.7). The top three listed reasons for the COVID-19 vaccine hesitancy were: negative information about the vaccine (32.90%), lack of enough information (21.80%), and vaccine safety concern (19.40%). The hesitancy of the COVID-19 vaccination uptake among diabetes patients was independently influenced by age between 40-49 (Adjusted Odd Ratio [AOR] = 4.52(1.04-19.66)), having vaccine awareness (AOR = 0.029(0.001-0.86)), having a great deal of trust on vaccine development (AOR = 0.028(0.002-0.52)), and a fear amount trust (AOR = 0.05(0.003-0.79)) on the vaccine preparation, vaccinated for COVID-19 (AOR = 0.13(0.04-0.51)), perceived exposure to COVID-19 infection after having the vaccine as strongly agree/agree (AOR = 0.03(0.01-0.17))and neither agree nor disagree (AOR = 0.07(0.02-0.30)). COVID-19 vaccine hesitancy among diabetic patients was relatively low. The identified independent predictors were age, vaccine awareness, COVID-19 vaccination history, awareness on vaccine preparation and exposure status to COVID-19 infection. The relevant agency should focus on efforts to translating these high levels of vaccine acceptance into actual uptake, through targeting identifying predictor variables and vaccine availability for a high-risk diabetes patient.

Application prospects of the 2BS cell-adapted China fixed rabies virus vaccine strain 2aG4-B40

BackgroundRabies is a fatal zoonotic disease whose pathogenesis has not been fully elucidated, and vaccination is the only effective method for protecting against rabies virus infection. Most inactivated vaccines are produced using Vero cells, which are African green monkey kidney cells, to achieve large-scale production. However, there is a potential carcinogenic risk due to nonhuman DNA contamination. Thus, replacing Vero cells with human diploid cells may be a safer strategy. In this study, we developed a novel 2BS cell-adapted rabies virus strain and analysed its sequence, virulence and immunogenicity to determine its application potential as a human diploid cell inactivated vaccine.Methods and resultsThe 2BS cell-adapted rabies virus strain 2aG4-B40 was established by passage for 40 generations and selection of plaques in 2BS cells. RNA sequence analysis revealed that mutations in 2BS cell-adapted strains were not located at key sites that regulate the production of neutralizing antibodies or virulence in the aG strain (GQ412744.1). The gradual increase in virulence (remaining above 7.0 logLD50/ml from the 40th to 55th generation) and antigen further indicated that these mutations may increase the affinity of the adapted strains for human diploid cells. Identification tests revealed that the 2BS cell-adapted virus strain was neutralized by anti-rabies serum, with a neutralization index of 19,952. PrEP and PEP vaccination and the NIH test further indicated that the vaccine prepared with the 2aG4-B40 strain had high neutralizing antibody levels (2.24 to 46.67 IU/ml), immunogenicity (protection index 270) and potency (average 11.6 IU/ml).ConclusionsIn this study, a 2BS cell-adapted strain of the 2aG4 rabies virus was obtained by passage for 40 generations. The results of sequencing analysis and titre determination of the adapted strain showed that the mutations in the adaptive process are not located at key sequence regions of the virus, and these mutations may enhance the affinity of the adapted strain for human diploid cells. Moreover, vaccines made from the adapted strain 2aG4-B40 had high potency and immunogenicity and could be an ideal candidate rabies virus strain for inactivated vaccine preparation.

KD-409, a Respiratory Syncytial Virus FG Chimeric Protein without the CX3C Chemokine Motif, Is an Efficient Respiratory Syncytial Virus Vaccine Preparation for Passive and Active Immunization in Mice.

Although respiratory syncytial virus (RSV) vaccine development initiatives have existed for half a century, no candidate has been approved for application at all ages from neonates to children. Developing an effective and safe RSV vaccine for pediatric use is challenging owing to RSV-associated disease and vaccine-enhanced disease (VED). We aimed to design an RSV vaccine, KD-409, by structurally incorporating the F ectodomain and G protein central conserved domain without the CX3C chemokine motif and test its efficacy and safety. KD-409 formed rosette particles or trimmers. KD-409 immunization of mice mainly induced anti-RSV F protein IgG. The induced anti-F antibodies had a higher IgG2a/IgG1 ratio than pre-fusion F, suggesting that they induced Th1-dominant immunity. Active and passive immunities were assessed by analyzing the viral titers in BALB/c mice intranasally challenged with RSV after intramuscular KD-409 immunization and pups derived from mothers who were intramuscularly vaccinated with KD-409 twice, respectively. KD-409 was more effective than post-fusion F and had a lower minimum effective dose than pre-fusion F. Thus, KD-409 demonstrated great potential as a novel RSV vaccine candidate, outperforming existing RSV F-based candidates. Our findings provide a promising strategy to overcome RSV-associated acute lower respiratory infections without the risk of VED associated with traditional approaches.