Construction and evaluation of a Salmonella Paratyphi A vaccine candidate based on a poxA gene mutation.

Salmonella Paratyphi A, the pathogen of paratyphoid A accounts for an obviously growing proportion of cases in many areas. Therefore, development of specific paratyphoid A vaccines is needed. In the present study, the poxA gene of Salmonella Paratyphi A, encoding the aminoacyl-tRNA synthetase, was deleted successfully by the method of lambda Red recombination system, the resulting strain, ΔpoxA was characterized in respect of growth, adhesion and invasion, virulence, immunogenicity and protective efficacy. It was found that the growth of the ΔpoxA strain was significantly delayed compared with the wild type strain, the mutant ΔpoxA was less invasive to Caco-2 BBE epithelioid cells and THP-1 macrophages than the wild type strain, strain ΔpoxA was attenuated at least 1000-fold in mice, significant immune response and efficient protection were provided by the mutant ΔpoxA after oral immunization. It is concluded that the Salmonella Paratyphi A poxA deletion mutant ΔpoxA can be used as a live oral vaccine candidate against paratyphoid A.

Oncolytic viruses alter the biogenesis of tumor extracellular vesicles and influence their immunogenicity.

Extracellular vesicles (EVs) are mediators of intercellular communication in the tumor microenvironment. Tumor EVs are commonly associated with metastasis, immunosuppression or drug resistance. Viral infections usually increase EV secretion, but little is known about the effect of oncolytic viruses (OVs) on tumor EVs. Here, we investigated the impact of oncolytic vesicular stomatitis virus (VSV) and vaccinia virus on EVs secreted by human melanoma and thoracic cancer cells. We found that OV infection increases the production of EVs by tumor cells. These EVs contain proteins of viral origin, such as VSV-G, thus creating a continuum of particles sharing markers of both canonical EVs and viruses. As such, the presence of VSV-G on EVs improves the transfer of their protein content to cell types commonly found in the tumor microenvironment. A proteomic analysis also revealed that EVs-OV secreted during VSV infection are enriched in immunity-related proteins. Finally, CD8+ T cells incubated with EVs-OV from infected cells display slightly enhanced cytotoxic functions. Taken together, these data suggest that OVs enhance the communication mediated by tumor EVs, which could participate in the therapeutic efficacy of OVs. These results also provide rationale for engineering OVs to exploit EVs and disseminate therapeutic proteins within the tumor microenvironment.

Experimental Validation of a Parenteral Permitted Daily Exposure Value for Cleaning-Induced Degradants from Recombinant Therapeutic Proteins with In Vitro Immunogenicity Assays.

Multiproduct manufacturing of biotherapeutic proteins generate cleaning-induced protein degradants because of extreme pH and temperature conditions during the cleaning process. Cleaning Acceptance limits are calculated based on the maximum allowable carryover (MAC) assessment of the previously manufactured active pharmaceutical ingredient (API) - or drug product - based on the permitted daily exposure (PDE) of the previously manufactured API into the dose of subsequent product. In this study, we tested a previously determined PDE value for cleaning-induced protein degradants of 650 µg/dose. A bench-scale cleaning method was used to generate cleaning induced degradants from both a half-life extension (HLE) BiTE® molecule and a mAb product. For this investigation degradants of HLE BiTE®-A and mAb-1 were characterized either alone or degradants of HLE BiTE®-A and mAb-1 spiked into mAb-1 at 650 µg. These samples were characterized by endotoxin testing, size exclusion chromatography (SEC), light obscuration by HIAC, and micro-fluidic imaging (MFI). These results suggest that significant degradation of the molecule occurs because of the cleaning procedure, and it is no longer in the intact form or active state. The biological impact was assessed using a cell line assay to assess immune activation, and a human Peripheral Blood Mononuclear Cell (PBMC) assay to assess T cell activation, T cell proliferation, and cytokine release after 20 hours and 7 days. Findings from the various in vitro cell-based assays suggest that the presence of 650 µg of carryover of degradants either alone or spiked into the same or a cross-product do not increase immunogenicity risk in cell-based assays - suggesting that the current PDE of 650 µg/dose for cleaning-induced degradant carryover does not have a risk of immunogenicity in patients.

Immunogenicity of concomitant SARS-CoV-2 and influenza vaccination in UK healthcare workers: a prospective longitudinal observational study.

Background: Co-administration of inactivated influenza vaccine (IIV) and SARS-CoV-2 vaccine may impact SARS-CoV-2 vaccine induced humoral immune responses. We aimed to compare IIV and SARS-CoV-2 vaccine induced cellular and humoral immune responses in those receiving concomitant vaccination to those receiving these vaccines separately. Methods: We conducted a cohort study between 29th September 2021 and 5th August 2022 in healthcare workers who worked at the local NHS trust and in the surrounding area that were vaccinated with a mRNA SARS-CoV-2 booster and cell-based IIV. We measured haemagglutination inhibition assay (HAI) titres, SARS-CoV-2 anti-spike antibody and SARS-CoV-2 ELISpot count pre-vaccination, 1-month and 6-months post-vaccination and evaluated differences by vaccine strategy. Findings: We recruited 420 participants, 234/420 (56%) were vaccinated concomitantly and 186/420 (44%) separately. The 1-month post-vaccination mean fold rise (MFR) in SARS-CoV-2 anti-spike antibodies was lower in those vaccinated concomitantly compared to separately (MFR [95% confidence interval (CI)] 9.7 [8.3, 11.4] vs 12.8 [10.3, 15.9], p = 0.04). After adjustment for age and sex, the adjusted geometric mean ratio (aGMR) remained lower for those vaccinated concomitantly compared to separately (aGMR [95% CI] 0.80 [0.70, 0.92], p = 0.001). At 6-months post-vaccination, we found no statistically significant difference in SARS-CoV-2 anti-spike antibody titres (aGMR [95% CI] 1.09 [0.87, 1.35], p = 0.45). We found no statistically significant correlation between vaccine strategy with SARS-CoV-2 ELISpot count and influenza HAI titres at 1-month and 6-months post-vaccination. Interpretation: Our study found that concomitant vaccination with SARS-CoV-2 and IIV has no statistically significant impacts on long-term immunogenicity. Further research is required to understand the underlying mechanisms and assess the clinical significance of reduced anti-spike antibodies in those vaccinated concomitantly. Funding: Research and Innovation (UKRI) through the COVID-19 National Core Studies Immunity (NCSi) programme (MC_PC_20060).

The self-assembled nanoparticle-based multi-epitope influenza mRNA vaccine elicits protective immunity against H1N1 and B influenza viruses in mice.

Introduction: The influenza virus is recognized as the primary cause of human respiratory diseases, with the current influenza vaccine primarily offering strain-specific immunity and limited protection against drifting strains. Considering this, the development of a broad-spectrum influenza vaccine capable of inducing effective immunity is considered the future direction in combating influenza. Methods: The present study proposes a novel mRNA-based multi-epitope influenza vaccine, which combines three conserved antigens derived from the influenza A virus. The antigens consist of M2 ion channel's extracellular domain (M2e), the conserved epitope of located in HA2 of hemagglutinin (H1, H3, B), and HA1 of hemagglutinin. At the same time, trimeric sequences and ferritin were conjugated separately to investigate the immune effects of antigen multivalent presentation. Results: Immunization studies conducted on C57BL/6 mice with these vaccines revealed that they can elicit both humoral immunity and CD4+ and CD8+ T cell responses, which collectively contribute to enhancing cross-protective effects. The virus challenge results showed that vaccinated groups had significantly reduced lung damage, lower viral loads in the lungs, nasal turbinates, and trachea, as well as decreased levels of pro-inflammatory cytokines. Conclusion: These findings clearly demonstrate the wide range of protective effects provided by these vaccines against H1N1 and B influenza viruses. The present finding highlights the potential of mRNA-based influenza vaccines encoding conserved proteins as a promising strategy for eliciting broad-spectrum protective humoral and cellular immunity against H1N1 and B influenza viruses.

Immunogenicity to Herpes Zoster recombinant subunit vaccine in immune-mediated rheumatic patients under treatment with JAK inhibitors.

OBJECTIVES: Patients with immune-mediated rheumatic diseases (IMRDs) face an elevated risk of varicella-zoster virus infection (VZV), and herpes zoster (HZ). Treatment with immunosuppressors further increases the risk. A new recently approved adjuvant recombinant inactive vaccine, offers safe protection against HZ. However, limited data exist on the efficacy of this new vaccine in patients with IMRDs treated with JAK inhibitors. We aimed to characterize B cell and T cell immune responses elicited by the HZ recombinant subunit vaccine in patients with IMRDs under treatment with JAK inhibitors, and to identify factors that might be associated with reduced immunogenicity, and therefore reduced protection. METHODS: We investigated humoral, and cellular CD4 and CD8 immune responses following a two-dose regimen of the recombinant inactive vaccine in 43 patients with rheumatic diseases treated with different JAK inhibitors. The responses were compared with age, gender and disease-matched healthy controls. RESULTS: Patients with IMRDs treated with JAK inhibitors showed reduced seroconversion rate (63% vs 100% and lower VZV IgG titers (1222 ± 411 vs 3048 ± 556, p< 0.0001) as compared with healthy controls. Functional T CD4 (IL-2 plus IFN-γ secretion) and T CD8 (Granzyme A and/or Granzyme B secretion) immune responses were also significantly diminished in IMRDs patients. Negative correlation was found between VZV antibody titers and age, specific treatments (baricitinib, tofacitinib, upadacitinib), cumulative methotrexate and glucocorticoid doses, history of multiple DMARDs, and treatment duration with JAK inhibitors. Functional T-CD4 responses but not functional T-CD8 responses also showed similar negative correlations. Positive associations were observed between functional T-CD4 and T-CD8 responses. CONCLUSIONS: Our study provides valuable insights into the immune responses elicited by the recombinant inactive vaccine in patients with IMRDs treated with JAK inhibitors. In these patients we have observed a broad impact on the adaptive humoral and cellular immune responses, suggesting a potential reduction in protection against herpes zoster infection and VHZ reactivation.

Safety and Immunogenicity of an Adjuvanted Clostridioides difficile Vaccine Candidate in Healthy Adults: A Randomized Placebo-Controlled Phase 1 Study.

BACKGROUND: This study investigated the safety, reactogenicity, and immunogenicity in healthy subjects of a Clostridioides difficile vaccine candidate with/without adjuvant, targeting toxins A and B. METHODS: In this first-in-human, phase 1, observer-blind study, subjects aged 18-45 years were randomized to receive F2 antigen (n = 10) or placebo (n = 10), and subjects aged 50-70 years to receive F2 antigen plus AS01 adjuvant (n = 45), F2 antigen (n = 45), or placebo (n = 30) in 2 doses 1 month apart. A subcohort (n = 40) received a third dose 15 months later. Solicited adverse events (AEs) were recorded for 7 days and unsolicited AEs for 30 days after each dose. Immunogenicity was assessed at baseline and after each dose. RESULTS: Solicited AEs were transient and most frequent in subjects receiving F2 antigen plus AS01. No serious AEs were considered related to study vaccine. Immunogenicity was substantially higher in subjects receiving F2 antigen plus AS01 than subjects receiving F2 antigen alone. A third dose increased the immune response in subjects with baseline neutralization titers below the assay lower limit of quantitation. CONCLUSIONS: The GSK C. difficile vaccine candidate was immunogenic, especially when given with AS01, and was well tolerated with an acceptable safety profile. CLINICAL TRIAL REGISTRATION: NCT04026009.

Bacterial infection with Clostridioides difficile can be severe or life threatening. A vaccine candidate to prevent C. difficile infection is being developed, containing a protein (F2 antigen) that stimulates the immune system to neutralize 2 C. difficile toxins. This is the first study investigating this vaccine candidate in people. Healthy people aged 18­45 years were given 2 doses of placebo or F2 antigen. People aged 50­70 years were given 2 doses of placebo, F2 antigen, or F2 antigen with an additional component (adjuvant) that helps stimulate the immune response. Some also received a third dose of F2 antigen or F2 antigen with adjuvant. The vaccine candidate was well tolerated with an acceptable safety profile. Injection site pain, tiredness, and headache were the most common side effects. The effects were mostly mild to moderate and transient, and were more frequently reported in the adjuvanted group, as expected. No serious safety events were considered related to the vaccine candidate. The vaccine candidate induced neutralization activity against both toxins, especially when given with adjuvant. In people with no measurable neutralization activity at the study start, a third dose increased the response. These findings offer potentially valuable insights for C. difficile vaccine development.

Immunogenicity analysis based on VP1 and VP2 proteins of bovine enterovirus.

Bovine enterovirus (BEV) infection manifests as a spectrum of clinical signs affecting the respiratory, gastrointestinal, and reproductive systems in cattle. Outbreaks of this disease results in large economic losses to the bovine industry worldwide. Currently there are no efficacious vaccines and medicines to prevent BEV infection. In the present study, reverse transcription-polymerase chain reaction was used to amplify the VP1 and VP2 genes of BEV, enabling the synthesis of a chimeric recombinant protein which contained partial sequences from both proteins. Subsequently, the emulsified purified proteins with Freund's adjuvant were used for triple-fold immunization of 4-week-old Institute of Cancer Research (ICR) mice. The mice were subsequently subjected to a challenge assay which elicited an immune response that was characterized by elevated titers of BEV-specific neutralizing antibodies. Notably, the results showed that the purification of pET32a-VP1 and pET32a-VP2 proteins markedly curtailed virus excretion and mitigated the histopathological damage usually associated with BEV infections. These were observed in the small intestines, kidneys and brain in infected animals. It also alleviated clinical symptoms such as hypothermia and weight loss. In summary, this study offers a theoretical and practical basis for BEV vaccine development.

Exploring the multiple therapeutic mechanisms and challenges of mesenchymal stem cell-derived exosomes in Alzheimer's disease.

Alzheimer's disease (AD) is a severe neurodegenerative disorder, and the current treatment options are limited. Mesenchymal stem cell-derived exosomes (MSC-Exos) have garnered significant attention due to their unique biological properties, showcasing tremendous potential as an acellular alternative therapy for AD. MSC-Exos exhibit excellent biocompatibility and low immunogenicity, enabling them to effectively cross the blood-brain barrier (BBB) and deliver therapeutic molecules directly to target cells. They are highly efficacious in delivering nucleic acid-based drugs. Moreover, the production process of MSC-Exos benefits from a high proliferation capacity and multilineage differentiation potential, allowing for production while maintaining a stable composition. Despite the significant theoretical advantages of MSC-Exos, their clinical use still faces multiple challenges, including cross-contamination during isolation and purification processes, the complexity of their components, and the presence of potential adverse paracrine factors. Future research needs to focus on optimizing separation and purification techniques, enhancing delivery methods to improve therapeutic efficacy, and performing detailed analyses of the components of MSC-Exos. In summary, MSC-Exos hold promise as an effective option for the treatment of AD and other neurodegenerative diseases, driving their clinical research and use in related fields.

Relative Effectiveness and Immunogenicity of Quadrivalent Recombinant Influenza Vaccine Versus Egg-Based Inactivated Influenza Vaccine Among Adults Aged 18-64 Years: Results and Experience From a Randomized, Double-Blind Trial.

Background: Immunogenicity studies suggest that recombinant influenza vaccine (RIV) may provide better protection against influenza than standard-dose inactivated influenza vaccines (SD IIV). This randomized trial evaluated the relative vaccine effectiveness (VE) and immunogenicity of RIV versus SD IIV in frontline workers and students aged 18-64 years. Methods: Participants were randomized to receive RIV or SD IIV and followed for reverse-transcription polymerase chain reaction (RT-PCR)-confirmed influenza during the 2022-2023 influenza season. Sera were collected from a subset of participants before and at 1 and 6 months postvaccination and tested by hemagglutination inhibition for A/H1N1, A/H3N2, B/Yamagata, and B/Victoria and against cell-grown vaccine reference viruses for A/H1N1 and A/H3N2. Results: Overall, 3988 participants were enrolled and vaccinated (25% of the trial sample size goal); RT-PCR-confirmed influenza occurred in 20 of 1963 RIV recipients and 28 of 1964 SD IIV recipients. Relative VE was 29% (95% confidence interval [CI], -26% to 60%). In the immunogenicity substudy (n = 118), the geometric mean titer ratio (GMTR) comparing RIV to SD IIV at 1 month was 2.3 (95% CI, 1.4-3.7) for cell-grown A/H1N1, 2.1 (95% CI, 1.3-3.4) for cell-grown A/H3N2, 1.1 (95% CI, .7-1.6) for B/Victoria, and 1.4 (95% CI, .9-2.0) for B/Yamagata. At 6 months, GMTRs were >1 against A/H1N1, A/H3N2, and B/Yamagata. Conclusions: Relative VE of RIV compared to SD IIV did not reach statistical significance, but RIV elicited more robust humoral immune responses to 2 of 4 vaccine viruses at 1 month and 3 of 4 viruses at 6 months after vaccination, suggesting possible improved and sustained immune protection from RIV. Clinical Trials Registration. NCT05514002.

Safety and immunogenicity of a ChAd155-vectored rabies vaccine compared with inactivated, purified chick embryo cell rabies vaccine in healthy adults.

BACKGROUND: Rabies is a zoonotic viral encephalitis that is endemic in many countries and confers a high mortality. Licensed vaccines require several doses to ensure efficacy. To investigate a logistically favorable approach, we assessed the safety and immunogenicity of ChAd155-RG, a novel investigational rabies vaccine using a replication-defective chimpanzee adenovirus vector. METHODS: We conducted a first-in-human, phase 1, randomized, double-blind, dose-escalation trial comparing ChAd155-RG with a licensed inactivated vaccine (RabAvert) in healthy adults. Participants received either RabAvert at standard dosing or ChAd155-RG at a low dose for one immunization or a high dose for one or two immunizations. To assess safety, we evaluated reactogenicity, unsolicited adverse events, and thrombotic events. To measure immunogenicity, we measured rabies viral neutralizing antibody (VNA) titers and anti-ChAd155 neutralizing antibodies. RESULTS: Mild to moderate systemic reactogenicity and transient lymphopenia and neutropenia were more common among recipients of ChAd155-RG compared with those who received RabAvert. No thrombotic events or serious adverse events were reported. Only the groups receiving RabAvert or two doses of high-dose ChAd155-RG achieved 100 % seroconversion, and seroprotection was most durable in the RabAvert group. Most participants had preexisting anti-vector antibodies, which were boosted by ChAd155-RG. Baseline and post-vaccination anti-vector antibody titers were negatively associated with post-vaccination rabies VNA titers. CONCLUSIONS: In this phase 1 clinical trial, a novel rabies vaccine using a simian adenovirus vector was safe and tolerable, but generated lower, less durable rabies VNA titers than a standard inactivated rabies virus vaccine, which may be due to preexisting, anti-vector immunity.

Pharmacokinetics and Safety of Intravenous Candidate Biosimilar CT-P47 and Reference Tocilizumab: A Randomized, Double-Blind, Phase 1 Study.

CT-P47 is a candidate biosimilar of tocilizumab. This 12-week, randomized, double-blind, parallel-design, phase 1 study aimed to demonstrate pharmacokinetic (PK) equivalence of CT-P47 and reference tocilizumab. Participants were healthy Japanese adults aged 18-55 years. Participants were randomized (1:1:1) to receive a single intravenous dose (8 mg/kg) of CT-P47, EU-approved tocilizumab (EU-tocilizumab), or US-licensed tocilizumab (US-tocilizumab). Primary PK endpoints were area under the concentration-time curve (AUC) from time zero to infinity, AUC from time zero to the last quantifiable concentration, and maximum serum concentration. Additional PK variables, safety, and immunogenicity were evaluated. The study was conducted from January 20 to May 26, 2023, in three centers in Japan. In total, 133 male participants were randomized (n = 45 to CT-P47, n = 44 to EU-tocilizumab, and n = 44 to US-tocilizumab). For all primary PK variables, 90% confidence intervals of the ratio of geometric least squares means were within the predefined equivalence margin of 0.80-1.25. Secondary PK variables were similar across groups. The most common treatment-emergent adverse event (TEAE) was neutrophil count decreased, occurring in 15 (33.3%), 13 (30.2%), and 12 (27.3%) participants in the CT-P47, EU-tocilizumab, and US-tocilizumab groups, respectively. There were no serious TEAEs, deaths, or study drug discontinuations due to TEAEs. Few participants were anti-drug antibody (ADA)- or neutralizing antibody (NAb)-positive. At the end of study, four (8.9%), one (2.3%), and two (4.5%) participants in the CT-P47, EU-tocilizumab, and US-tocilizumab groups, respectively, were ADA-positive; two (4.4%), zero (0%), and one (2.3%) in the respective groups were NAb-positive. CT-P47 demonstrated PK equivalence and comparable safety to EU- and US-tocilizumab.

Bibliometrics analysis and knowledge mapping of pertussis vaccine research: trends from 1994 to 2023.

PURPOSE: This study aims to use bibliometric methods to explore the evolving landscape, hotspots, and emerging frontiers of pertussis vaccine research, providing deeper insights into the current research landscape and guiding future vaccine development efforts. METHODS: We conducted a comprehensive search of the Web of Science Core Collection database (WoSCC) from January 1, 1994, to December 31, 2023, employing search terms related to vaccination (vacc* or immun*) and pertussis (pertussis, Whooping Cough, Bordetella pertussis, B. pertussis, Bordetella pertussis infection, or B. pertussis infection) in the Title or Author keywords fields. Bibliometrics analysis of pertussis research was performed utilizing the bibliometrix-biblioshiny package in RStudio, alongside CiteSpace and VOSviewer software. RESULTS: In total, 2,623 records were analyzed, comprising 89.63% (n = 2,351) original research articles and 10.37% (n = 272) review articles. The study revealed that academic research on the pertussis vaccine was growing at a rate of 4.64% per year. The United States and Canada lead in the number of publications. GlaxoSmithKline and the Centers for Disease Control & Prevention- United States emerged as leading institutions, with Halperin SA and Locht C as the most active authors. Vaccine was the most influential journal. Most studies focused on vaccine effectiveness duration, vaccination schedules for high-risk groups, and people's attitudes toward vaccination. CONCLUSION: Our analysis showed increasing interest of researchers in pertussis literature, yet current research mainly emphasized expanding vaccine coverage and optimizing strategies, neglecting new vaccine development. This emphasized the need for prioritizing novel pertussis vaccines to tackle the resurgence challenge.

A novel orf virus vector-based COVID-19 booster vaccine shows cross-neutralizing activity in the absence of anti-vector neutralizing immunity.

Next-generation COVID-19 vaccines are being developed to expand the breadth of coverage against existing and future variants and to extend the duration of protection. Prime-2-CoV_Beta is an orf virus (ORFV) based multi-antigen COVID-19 vaccine that co-expresses Spike (S) and Nucleocapsid (N) antigens. The safety and immunogenicity of Prime-2-CoV_Beta is investigated in a phase 1 first-in-human (FIH) dose-finding trial (ORFEUS study, ClinicalTrials.gov: NCT05367843). Participants of two age groups (18-55 and 65-85 years) who previously completed at least two doses of mRNA vaccines were enrolled and sequentially assigned to different dose groups to receive one intramuscular dose of 3 × 105, 3 × 106, 1.5 × 107, or 3 × 107 plaque-forming units (PFU) of Prime-2-CoV_Beta on day 1 and a second dose on day 29. Here, we report safety and immunogenicity data collected up to 6 months after the first study vaccination. Prime-2-CoV_Beta is safe and well tolerated and elicits immune responses at higher dose levels in participants aged 18-55. A single dose of 3 × 107 PFU boosted binding and cross-neutralizing antibody responses that are maintained through 6 months after the first booster vaccination. Polyfunctional S-specific CD4+ and CD8+ T cell responses are observed after vaccination. No pre-existing or vaccine-induced neutralizing anti-vector antibodies are detected. Our findings highlight the potential of the ORFV vector as a safe platform for future vaccine design, which provides the ability to deliver multiple antigens and allows for repeat immunization.

Smoking and serological response to influenza vaccine.

Cigarette smoking confers additional risk from influenza. This study assessed the effect of smoking on humoral immune response to influenza vaccine. Adults ≥50 y of age were enrolled during the 2011-2016 influenza vaccination seasons in an observational prospective study. Non-fasting whole blood samples for hemagglutination inhibition (HAI) assays were obtained from participants at pre- and 28 d post-clinically administered, trivalent influenza vaccination. Among 273 participants, 133 subjects self-reported as never smokers, 87 as ex-smokers, and 53 as current smokers. Postvaccination geometric mean HAI titers were significantly higher among smokers for A/H1N1 (p = .031) and A/H3N2 (p = .001). Relative to never smokers, smoking was independently related to seroconversion to A/H1N1, A/H3N2 and B. The adjusted odd ratios (ORs) were 5.2 [95% confidence interval (CI), 2.3, 11.5] for seroconversion to A/H1N1, 5.4 (95% CI, 2.4, 12.1) for A/H3N2, and 2.7 (95% CI, 1.3, 5.7) for B. Smoking was also independently related to seroprotection to A/H1N1, A/H3N2 and B. The ORs were 3.6 (95% CI, 1.6, 8.08) for seroprotection to A/H1N1 in smokers, 2.7 (95% CI, 1.14, 6.5) for A/H3N2, and 2.5 (95% CI, 1.1, 5.7) for B. Although the mechanism is unclear, smokers showed a better immune response to influenza vaccination than never smokers and ex-smokers. The results can be used to emphasize the value of influenza vaccination for smokers.

Using Spectral Flow Cytometry for CAR T-Cell Clinical Trials: Game Changing Technologies Enabling Novel Therapies.

Monitoring chimeric antigen redirected (CAR) T-cells post-infusion in clinical trials is a specialized application of flow cytometry. Unlike the CAR T-cell monitoring for individual patients conducted in clinical laboratories, the data generated during a clinical trial will be used not only to monitor the therapeutic response of a single patient, but determine the success of the therapy itself, or even of an entire class of therapeutic compounds. The data, typically acquired at multiple testing laboratories, will be compiled into a single database. The data may also be used for mathematical modeling of cellular kinetics or to identify predictive biomarkers. With the expanded context of use, a robust, standardized assay is mandatory in order to generate a valuable and reliable data set. Hence, the requirements for assay validation, traceable calibration, technology transfer, cross-instrument standardization and regulatory compliance are high.

Mesenchymal Stem Cells Derived from Human Urine-Derived iPSCs Exhibit Low Immunogenicity and Reduced Immunomodulatory Profile.

Human-induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) represent a promising and renewable cell source for therapeutic applications. A systematic evaluation of the immunological properties and engraftment potential of iMSCs generated from urine-derived iPSCs is lacking, which has impeded their broader application. In this study, we differentiated urine-derived iPSCs into iMSCs and assessed their fundamental MSC characteristics, immunogenicity, immunomodulatory capacity and in vivo engraftment. Compared to umbilical cord-derived MSCs (UCMSCs), iMSCs demonstrated an enhanced proliferative capacity, a higher level of regenerative gene expression, and lower immunogenicity, strengthening resistance to apoptosis induced by allogeneic peripheral blood mononuclear cells (PBMCs) and the NK-92 cell line. In addition, iMSCs exhibited a diminished ability to inhibit T cell proliferation and activation compared with UCMSCs. Transcriptomic analyses further revealed the decreased expression of immune regulatory factors in iMSCs. After transfusion into mouse models, iMSCs engrafted in the lungs, liver, and spleen and exhibited the ability to migrate to tumor tissues. Our results indicated that iMSCs generated from urine-derived iPSCs have a significant replicative capacity, low immunogenicity and unique immunomodulatory properties, and hence offer obvious advantages in immune privilege and allogenic therapeutic application prospects.

Safety and immunogenicity of a modified mRNA-lipid nanoparticle vaccine candidate against COVID-19: Results from a phase 1, dose-escalation study.

This phase 1, open-label, dose-escalation, multi-center study (NCT05477186) assessed the safety and immunogenicity of a booster dose of an mRNA COVID-19 vaccine (CV0501) encoding the SARS-CoV-2 Omicron BA.1 spike protein. Participants aged ≥ 18 years previously vaccinated with ≥ 2 doses of an mRNA COVID-19 vaccine received CV0501 doses ranging from 12 to 200 µg. After assessment of safety and immunogenicity of the 12 µg dose in 30 adults, 30 adults ≤ 64 years were randomized to receive either a 3 or 6 µg dose. Solicited adverse events (AEs) were collected for 7 days, unsolicited AEs for 28 days, and serious AEs (SAEs), medically attended AEs (MAAEs), and AEs of special interest (AESIs) until day (D) 181 post-vaccination. Serum neutralizing titers specific to SARS-CoV-2 BA.1, wild-type, Delta, and additional Omicron subvariants were assessed at D1, D15, D29, D91, and D181. Of 180 vaccinated participants (mean age: 49.3 years; 57.8% women), 70.6% had prior SARS-CoV-2 infection. Most solicited local (98.1%) and systemic (96.7%) AEs were of mild-to-moderate severity; the most common were injection site pain (57.5%; 33.3-73.3% across groups) and myalgia (36.9%; 13.3-56.7%). Unsolicited AEs were reported by 14.4% (6.7-26.7%) of participants (mild-to-moderate severity in 88.5% of the participants). Three participants (1.7%) reported SAEs, 16.7% (6.7-30.0%) reported MAAEs, and 8.3% (0.0-13.3%) reported AESIs (15 COVID-19 cases), none related to vaccination. Geometric means of serum neutralizing titers increased from baseline to D15 and D29 (dose-dependent), and then decreased over time. The safety and immunogenicity results supported advancement to a phase 2 trial.

What is the context? Since 2019, more than 776 million people have been infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide, and more than 7 million people have died due to COVID-19.The virus changes over time and new variants may evade the protection provided by vaccines that are effective against previous variants.Therefore, it is necessary to develop vaccines that can be quickly updated to better protect against COVID-19 caused by new SARS-CoV-2 variants.We developed an mRNA vaccine, CV0501, that encodes a key protein on the surface of the SARS-CoV-2 Omicron BA.1 variant to instruct the immune system for future protection against COVID-19. The mRNA is encased in lipid nanoparticles that can increase the immune response to the vaccine.What is new? We administered different dose levels (that is, different amounts of mRNA) of CV0501 to adults who had previously been vaccinated at least twice with a different COVID-19 vaccine.We found that even at increased dose levels, CV0501 caused mostly mild side effects that resolved within a few days. Serious adverse events or events that required medical attention were not related to the vaccine.We also found that CV0501 generated immune responses not only against the Omicron BA.1 subvariant (vaccine antigen) but also against the original SARS-CoV-2 variant, the Delta variant, and other Omicron subvariants, at all dose levels tested.What is the impact? Our findings indicate that the CV0501 vaccine was well tolerated and induced immune responses against vaccine target variant as well as other SARS-CoV-2 variants.Other vaccines against COVID-19 based on the mRNA technology used for CV0501 will be further evaluated.

Japanese Subgroup Analyses from EMERGE and ENGAGE, Phase 3 Clinical Trials of Aducanumab in Patients with Early Alzheimer's Disease.

BACKGROUND: Global prevalence and incidence of dementia continue to rise at a rapid rate. There is a need for new Alzheimer's disease (AD) treatments globally. Aducanumab is a human monoclonal antibody that selectively targets aggregated soluble amyloid beta oligomers and insoluble amyloid beta fibrils. In June 2021, aducanumab was approved by the US Food and Drug Administration for the treatment of AD under the accelerated approval pathway. OBJECTIVES: We evaluated the efficacy, safety, biomarker and pharmacokinetics (PK) of aducanumab in Japanese subgroups in EMERGE and ENGAGE studies. DESIGN: EMERGE and ENGAGE were two randomized, double-blind, placebo-controlled, global, phase 3 studies of aducanumab in patients with early AD (mild cognitive impairment due to AD or mild AD dementia). SETTING: These studies involved 348 sites in 20 countries. PARTICIPANTS: Participants enrolled in Japan included 121 (7.4% of total 1638 in EMERGE) and 100 (6.1% of total 1647 in ENGAGE) patients (aged 50-85 years with confirmed amyloid pathology) who met clinical criteria for mild cognitive impairment due to AD or mild AD dementia. INTERVENTION: Participants were randomly assigned 1:1:1 to receive aducanumab low dose (3 or 6 mg/kg target dose), high dose (6 or 10 mg/kg target dose) or placebo via IV infusion once every 4 weeks over 76 weeks. MEASUREMENTS: The primary outcome measure was change from baseline to Week 78 on the Clinical Dementia Rating Sum of Boxes (CDR-SB), an integrated scale that assesses both function and cognition. Other measures included safety assessments; secondary and tertiary clinical outcomes that assessed cognition, function, and behavior; biomarker endpoints (amyloid PET and plasma p-tau181); serum PK profiles and immunogenicity. RESULTS: Results from the Japanese subgroup analyses were generally consistent with those of the overall study population across endpoints, while a lower mean body weight (kg) and a smaller proportion of ApoE ε4 carriers were observed in the Japanese subgroup population. A treatment effect was observed in favor of aducanumab on the primary and secondary efficacy endpoints at Week 78 in EMERGE, but not ENGAGE. The incidence and type of adverse events in the Japanese subgroups were generally comparable to those observed in the overall study population; amyloid related imaging abnormalities (ARIA) were common treatment-related adverse events that appeared to be related to the aducanumab dose. ARIA incidence was generally lower in the Japanese subgroup compared with the overall population. Consistent with the overall data set, a robust dose-dependent decrease in amyloid beta levels as assessed with amyloid-PET and plasma p-tau181 was observed. Serum PK profiles and immunogenicity of aducanumab in Japanese population were consistent with the non-Japanese population. CONCLUSION: Efficacy, safety, biomarker, and PK profiles of aducanumab were consistent between the Japanese subgroup and the overall population. A positive treatment effect of aducanumab on efficacy endpoints was observed in EMERGE, but not in ENGAGE.

Signal peptide exchange alters HIV-1 envelope antigenicity and immunogenicity.

Introduction: HIV-1 envelope (Env) is the key target for antibodies (Abs) against the virus and thus an important HIV-1 vaccine component. Env is synthesized from a gp160 precursor with a signal peptide (SP) at its N-terminus. This study investigated the influence of the SP on Env antigenicity and immunogenicity. Methods: Env proteins from two HIV-1 isolates, AA05 and AC02, were analyzed as gp120 and gp160 in their native wild-type (WT) forms and as chimeras with swapped SPs (AA05-02 and AC02-05). The WT and chimeric Env were assessed for antigenicity and glycosylation using monoclonal antibodies (mAbs) and glycan probes. Immunogenicity was tested in mice using three vaccine types: gp120 protein, gp120 DNA+gp120 protein, and gp120 DNA+gp160 DNA. Results: The recombinant AC02 gp120 protein was antigenically superior to AA05 as indicated by higher reactivity with most mAbs tested. When SPs were swapped, the antigenicity of the chimeric gp120s (AA05-02 and AC02-05) resembled that of the gp120s from which the SPs were derived; AA05-02 was similar to AC02 and vice versa. Glycan probe reactivity followed a similar pattern: AA05-02 and AC02 showed similar affinity to high-mannose specific mAbs and lectins. Interestingly, the antigenicity of gp160s showed an opposite pattern; membrane-bound gp160 expressed with the AA05 SP (AA05 and AC02-05) showed greater mAb binding than gp160 with the AC02 SP (AC02 and AA05-02). Mice immunized with gp120 protein showed that AA05-02 induced stronger cross-reactive binding Ab responses than AA05 WT, and AC02 elicited stronger responses than AC02-05, indicating AC02 SP enhanced gp120 immunogenicity. However, when DNA vaccines were included (gp120 DNA+gp120 protein and gp120 DNA+gp160 DNA), the use of heterologous SPs diminished the immunogenicity of the WT immunogens. Among the three vaccine regimens tested, only gp120 DNA+gp160 DNA immunization elicited low-level Tier 2 neutralizing Abs, with AA05 WT inducing Abs with greater neutralization capabilities than AA05-02. Conclusion: These data demonstrate that the SP can significantly impact the antigenicity and immunogenicity of HIV-1 Env proteins. Hence, while SP swapping is a common practice in constructing Env immunogens, this study highlights the importance of careful consideration of the effects of replacing native SPs on the immunogenicity of Env vaccines.