Protein Vaccine Research Articles

Phase I clinical trial to assess the safety of pNGVL4aCRTE6E7L2 DNA and TA-CIN protein vaccinations and to seek the appropriate dose of the pNGVL4aCRTE6E7L2 DNA vaccine

Phase I clinical trial to assess the safety of pNGVL4aCRTE6E7L2 DNA and TA-CIN protein vaccinations and to seek the appropriate dose of the pNGVL4aCRTE6E7L2 DNA vaccine

Experimental and Numerical Integrated Strategy for the Optimization of Microfluidic Parameters for Eudragit L100 Nanoparticles and Microparticles.

Oral immunization offers a minimally invasive administration, inducing local and systemic immune responses and facilitating mass immunization without needle-related risks. However, the gastrointestinal environment poses challenges, compromising vaccine effectiveness through enzymatic degradation and poor absorption by Peyer's patches. Advances in nanoparticle and microparticle (NP/MP) technology protect vaccines from degradation and enhance targeted release. The aim of this study was to develop pH-controlled polymeric carriers for the oral delivery of protein vaccines in order to target the antigen-presenting cells and M cells in the region of Peyer's patches. Here, myoglobin was chosen as a model protein vaccine. This study focuses on Eudragit L100, a pH-responsive polymer stable in acidic conditions and dissolving at higher pH, to develop carriers for controlled myoglobin release in the intestinal tract. A microfluidic-based manufacturing process for Eudragit L100 NPs and MPs is optimized using a comprehensive experimental and computational approach to obtain NPs and MPs through the same setup. Integrating in silico and experimental methods highlights the potential of numerical simulations to streamline final product development. This approach improves the efficiency and cost-effectiveness of NP/MP production, demonstrating how the combination of design of experiment and numerical simulations can optimize production parameters and refine manufacturing processes for advanced drug delivery systems.

Amplification of Protein Expression by Self-Amplifying mRNA Delivered in Lipid Nanoparticles Containing a β-Aminoester Ionizable Lipid Correlates with Reduced Innate Immune Activation.

Self-amplifying mRNA (saRNA) is witnessing increased interest as a platform technology for protein replacement therapy, gene editing, immunotherapy, and vaccination. saRNA can replicate itself inside cells, leading to a higher and more sustained production of the desired protein at a lower dose. Controlling innate immune activation, however, is crucial to suppress unwanted inflammation upon delivery and self-replication of RNA in vivo. In this study, we report on a class of β-aminoester lipids (βAELs) synthesized through the Michael addition of an acrylate to diethanolamine, followed by esterification with fatty acids. These lipids possessed one or two ionizable amines, depending on the use of nonionic or amine-containing acrylates. We utilized βAELs for encapsulating saRNA in lipid nanoparticles (LNPs) and evaluated their transfection efficiency in vitro and in vivo in mice, while comparing them to LNPs containing ALC-0315 as an ionizable lipid reference. Among the tested lipids, OC7, which comprises two unsaturated oleoyl alkyl chains and an ionizable azepanyl motif, emerged as a βAEL with low cytotoxicity and immunogenicity relative to ALC-0315. Interestingly, saRNA delivered via the OC7 LNP exhibited a distinct in vivo transfection profile. Initially, intramuscular injection of OC7 LNP resulted in low protein expression shortly after administration, followed by a gradual increase over a period of up to 7 days. This pattern is indicative of successful self-amplification of saRNA. In contrast, saRNA delivered via ALC-0315 LNP demonstrated high protein translation initially, which gradually declined over time and lacked the amplification seen with OC7 LNP. We observed that, in contrast to saRNA OC7 LNP, saRNA ALC-0315 LNP induced potent innate immune activation by triggering cytoplasmic RIG-I-like receptors (RLRs), likely due to the highly efficient endosomal membrane rupturing properties of ALC-0315 LNP. Consequently, the massive production of type I interferons quickly hindered the amplification of the saRNA. Our findings highlight the critical role of the choice of ionizable lipid for saRNA formulation in LNPs, particularly in shaping the qualitative profile of protein expression. For applications where minimizing inflammation is desired, the use of ionizable lipids, such as the βAEL reported in this study, that elicit a low type I interferon response in saRNA LNP is crucial.

Recombinant RSV G protein vaccine induces enhanced respiratory disease via IL-13 and mucin overproduction

The G protein expressed on the surface of respiratory syncytial virus (RSV) is important for adhesion to host cells and as a vaccine target antigen. The corresponding vaccines can effectively eliminate RSV. However, they exacerbate pulmonary immunopathology including eosinophilic infiltration in the lungs after an RSV challenge in animal models, raising concerns about enhanced respiratory disease (ERD); thus, approaches that mitigate these effects are urgently needed. Herein, we aimed to examine the mechanisms of G protein vaccine-induced ERD in mice, using recombinant G protein as a vaccine antigen. After the RSV challenge, G protein-vaccinated mice exhibited lung weight gain, lung tissue damage, and increased infiltration of eosinophils, neutrophils, and CD4+ T cells into the lungs. We set lung weight gain as the endpoint for ERD and examined the impact of each infiltrating cell on lung weight gain. We observed that CD4+ T cells, but not eosinophils or neutrophils, that infiltrate the lungs are responsible for lung weight gain. In addition, T helper 2 cell-mediated IL-13 induced mucin hypersecretion and lung weight gain. Mucin hypersecretion may contribute to weight gain in the lungs. In conclusion, our results indicate a novel mechanism of G protein vaccine-induced ERD via IL-13 and mucin hypersecretion, which could lead to the development of safe G protein vaccines and the elucidation of the causes of ERD associated with other vaccines.

Enhancement of protective efficacy of recombinant attenuated Salmonella typhimurium delivering H9N2 avian influenza virus hemagglutinins(HA) antigen vaccine candidate strains by C-C motif chemokine ligand 5 in chickens(chCCL5)

The H9N2 inactivated avian influenza vaccine cannot induce cellular and mucosal immune responses, while the attenuated Salmonella vector as an intracellular bacterium can induce dominant cellular and mucosal immune responses. However, it provides low protection against the virus when delivering viral antigens and needs further optimization. Chicken C-C motif chemokine ligand 5 (chCCL5) is an important CC chemokine associated with immune cell chemotaxis, migration, and viral infection. This study connected the sequence of chCCL5 (CCL5) with the hemagglutinin sequence of the H9N2 avian influenza virus (yH9HA), utilizing the attenuated Salmonella typhimurium vector containing the delayed lysis system MazE/F regulated by arabinose as a carrier. A vaccine strain of recombinant attenuated Salmonella typhimurium and H9N2 avian influenza virus HA, rSC0130 (pS0017-yH9HA-CCL5), was successfully constructed. The experimental results indicate that yH9HA-CCL5 can be expressed in 293 T cells; compared to the strain without CCL5, rSC0130 (pS0017-yH9HA-CCL5) can induce significantly increased cellular immune responses and provide better protective effects in H9N2 virus challenge experiments. The above results indicate that chCCL5 can significantly enhance the protective effect of Salmonella delivering H9N2 avian influenza virus HA protein vaccine against H9N2 avian influenza virus infection, providing valuable theoretical support for further improving the protective efficiency of recombinant attenuated Salmonella vectors for delivering viral antigens.

Serological responses to target Streptococcus pyogenes vaccine antigens in patients with proven invasive beta-haemolytic streptococcal infections.

Rising incidence of invasive beta-haemolytic streptococcal (iBHS) infections has prompted consideration of vaccination as a preventative strategy for at-risk populations. The benefits of a vaccine targeting Lancefield group A (Streptococcus pyogenes; Strep A) would increase if cross-species immunity against Lancefield groups C/G (Streptococcus dysgalactiae subspecies equisimilis; SDSE) and B (Streptococcus agalactiae; GBS) was demonstrated. A prospective, observational study of adult patients with iBHS infections due to Strep A, SDSE or GBS. Antibody responses to six Strep A candidate antigens were assayed on acute and convalescent sera. A serological response was defined as an increase of >0.2log10 arbitrary units/mL (AU/mL). Sixty-seven participants were enrolled. Thirty-three participants were included in the final analysis (12, 11 and 10 with Strep A, SDSE and GBS, respectively). The median serological response for participants with Strep A was significant for all tested antigens (median >0.2log10 difference between acute and convalescent samples; P<0.05 for all). Those with SDSE had comparable and significant median (IQR) responses to streptolysin-O (0.65 [0.36-1.67], P=0.004), S. pyogenes adhesion and division protein (0.68 [0.36-1.63], P=0.005) and C5a peptidase (ScpA; 0.30 [0.23-1.06]), P=0.004). GBS responses were limited to ScpA only (0.34 [0.08-0.52], P=0.05). Patients with invasive Strep A infection mount robust antibody responses to six non-M protein vaccine candidate antigens. Similar significant responses to C5a peptidase in those with invasive SDSE and GBS infection highlight the importance of further research into cross-species protection and immunological correlates of vaccine efficacy.

CT584 Is Not a Protective Vaccine Antigen against Respiratory Chlamydial Challenge in Mice.

Background:Chlamydia trachomatis is the most prevalent bacterial sexually transmitted pathogen in humans worldwide. Since chlamydial infection is largely asymptomatic with the potential for serious complications, a preventative vaccine is likely the most viable long-term answer to this public health threat. Cell-free protein synthesis (CFPS) utilizes the cellular protein manufacturing machinery decoupled from the requirement for maintaining cellular viability, offering the potential for flexible, rapid, and decentralized production of recombinant protein vaccine antigens. Methods: Here, we use CFPS to produce the full-length putative chlamydial type three secretion system (T3SS) needle-tip protein, CT584, for evaluation as a vaccine antigen in mouse models. High-speed atomic force microscopy (HS-AFM) (RIBM, Tsukuba, Japan) imaging and computer simulations confirm that CFPS-produced CT584 retains a native-like structure prior to immunization. Female mice were primed with CT584 adjuvanted with CpG-1826 intranasally (i.n.) or CpG-1826 + Montanide ISA 720 intramuscularly (i.m.), followed four weeks later by an i.m. boost before respiratory challenge with 104 inclusion forming units (IFU) of Chlamydia muridarum. Results: Immunization with CT584 generated robust antibody responses but weak cell-mediated immunity and failed to protect against i.n. challenge as demonstrated by body weight loss, increased lung weights, and the presence of high numbers of IFUs in the lungs. Conclusion: While CT584 was not a protective vaccine candidate, the speed and flexibility with which CFPS can be used to produce other potential chlamydial antigens make it an attractive technique for antigen production.

Evaluation of Protective Efficacy of Recombinant Toxoplasma gondii DDX39 Protein Vaccine against Acute and Chronic T. gondii Infection in Mice

Toxoplasma gondii, a pervasive parasite responsible for toxoplasmosis, poses significant health risks to humans and animals. In this study, we investigated the immunogenicity and protective efficacy of the recombinant T. gondii DDX39 protein formulated with ISA201 adjuvant (rTgDDX39) as a candidate vaccine against toxoplasmosis. The full-length of TgDDX39 gene was successfully amplified, cloned into the pET-30a vector, and expressed in BL21 (DE3) competent cells, which was purified and identified as a 57.1 kDa protein via sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Western blot analysis confirmed that rTgDDX39 was specifically recognized by serum from T. gondii-infected mice. Furthermore, immunization of rats with rTgDDX39 generated antiserum that could specifically recognize the native TgDDX39 protein in T. gondii tachyzoite lysates. Immunofluorescence assay revealed that TgDDX39 was primarily located in the nucleus and perinuclear region of tachyzoites. Our vaccination strategy significantly increased T cell proliferation, with CD4+ T cells rising by 21.9% and CD8+ T cells by 57.8% by the sixth week compared to the adjuvant control group. Additionally, high titers of anti-rTgDDX39 IgG antibodies were detected in vaccinated mice, with a notable induction of IgG1 and IgG2a isotypes, and IgG1/IgG2a > 1 suggests a Th2-biased immune response.Furthermore, in vitro and in vivo assays demonstrated that polyclonal antibodies raised against rTgDDX39 could inhibit the proliferation of T. gondii RH tachyzoites, highlighting the potential of these antibodies to neutralize this parasite effectively. This study provides compelling evidence of the immunogenicity and protective efficacy of rTgDDX39, supporting its potential as a potential candidate vaccine against toxoplasmosis. The protective efficacy of the vaccine was evaluated in mice challenged with acute (RH) and chronic (PRU) strains of T. gondii, showing a survival time extended to 17 days in the acute model, compared to 13.5 and 14 days in the control groups, and a significant 34% reduction in cyst burden in the chronic model. Additionally, the survival rate in the PRU-infected mice increased from 15-20% in the control groups to 45% in the vaccinated group. In vitro and in vivo assays demonstrated that polyclonal antibodies raised against rTgDDX39 could inhibit the proliferation of T. gondii RH tachyzoites, highlighting the potential of these antibodies to neutralize the parasite effectively. This study provides compelling evidence of the immunogenicity and protective efficacy of rTgDDX39, supporting its potential as a candidate vaccine against toxoplasmosis.

Effects of age and gender on immunogenicity and reactogenicity of SpikoGen recombinant spike protein vaccine: a post-hoc analysis

SpikoGen® COVID-19 vaccine is based on the spike protein extracellular domain of the ancestral Wuhan-Hu-1 strain modified by removal of the furin cleavage site and addition of stabilising mutations expressed as a recombinant protein in insect cells. It is formulated with Advax-CpG55.2™ adjuvant to ensure optimal immunogenicity. In this study, data from several SpikoGen® clinical trials was retrospectively analysed to assess for any effect of gender or age on seroconversion, neutralizing antibody levels or the incidence of adverse events. Following the 1st dose, older age was associated with a reduced rate of fatigue (RR 0.97, p < 0.001), headache (RR 0.98, p = 0.034) and myalgia (RR 0.97, p=0.016), following the 2nd dose, the rate of fatigue (RR 0.98, p = 0.017) but following the 3rd dose no effect of age on adverse events was evident. Similarly, following the 1st dose, men reported a 19% lower incidence of fatigue, 36% lower incidence of headache and 28% lower incidence of myalgia when compared to women. Interestingly, there was no relationship between age or gender and serum neutralizing antibody levels, although after each vaccine dose there was a consistent trend to women having a higher seroconversion rate. There was no correlation between neutralizing antibody levels and adverse events. Unlike what is seen with mRNA vaccines, reactogenicity trended lower after each subsequent SpikoGen® dose. Overall, SpikoGen® exhibited positive immunogenicity and low reactogenicity, indicating that a low incidence of adverse events does not equate to poor immunogenicity. SpikoGen® remains a promising protein-based vaccine platform for COVID-19 protection.

A multi-epitope protein vaccine encapsulated in alginate nanoparticles as a candidate vaccine against Shigella sonnei

Shigellosis, caused by the Gram-negative bacterium Shigella, is a major global health challenge. Despite extensive research over the past two decades, no commercial vaccine is available to prevent Shigella infection. Developing multi-epitope vaccines offers a promising and innovative approach to tackling infectious diseases. In this study, we produced a multi-epitope vaccine candidate using E. coli BL21 (DE3) plysS bacteria and purified the vaccine protein with Ni-NTA affinity chromatography. We then prepared alginate nanoparticles containing the vaccine protein, with a particle size of 122 ± 6 nm, PDI 0.17, SPAN 0.83, and zeta potential of -27 ± 2 mV. Successful protein loading was confirmed through nanodrop and ATR-FTIR analyses. To evaluate the immunogenicity of the encapsulated vaccine, mice were orally vaccinated, and their serum was analyzed for IgG, IL-4, and IFN-γ levels cytokines. The results showed a significant increase in IgG level in the vaccinated group compared to controls. Additionally, the vaccinated group exhibited a notable increase in IL-4 and IFN-γ cytokines, indicating a robust Th-cell-mediated immune response essential for combating Shigella. Our nano-vaccine demonstrated high efficacy in activating both humoral and cellular immunity, effectively protecting against the bacteria. The alginate-based oral vaccine candidate thus emerges as a promising strategy for developing a multi-epitope vaccine candidate against Shigella.

Immunogenicity and safety of SARS-CoV-2 recombinant spike protein vaccine in South African people living with and without HIV-1 infection: A phase 2 randomised trial

BackgroundResponse data for COVID-19 vaccines in immunosuppressed individuals are typically limited to standard dosing in small populations. Adjusting number or interval of doses may impact immune responses based on HIV status. MethodsThis phase 2 randomised, observer-blinded, placebo-controlled South African study (2019nCoV-505/NCT05112848) enrolled medically stable people living with HIV (PLWH) and HIV-uninfected participants aged 18–65 years. PLWH were randomised 1:1:1 to receive NVX-CoV2373 on day 0 (D0) and either D21 (2-DoseD0/D21) or D70 (2-DoseD0/D70), or on D0, D21, and D70 (3-Dose). HIV-uninfected participants were randomised 1:1 to each 2-Dose regimen. PLWH were stratified into well-controlled and less–well-controlled subgroups. The primary immunologic endpoint included serum IgG and neutralising antibody responses (per geometric mean fold rise [GMFR] in titre and seroconversion rate) to ancestral SARS-CoV-2 at D35 (2-DoseD0/D21) and D84 (2-DoseD0/D70 and 3-Dose). The primary safety endpoints were participants with an unsolicited adverse event through D84, at D120, and at D180, or reactogenicity ≤7 days post-vaccination. ResultsOf 288 PLWH, 98, 96, and 94 were randomised into the 2-DoseD0/D21, 2-DoseD0/D70, and 3-Dose groups, respectively; 96 HIV-uninfected participants were randomised to the 2-DoseD0/D21 (n=47) or 2-DoseD0/D70 (n=49) regimens. Most (>85%) of the population were SARS-CoV-2 positive at baseline. Ancestral anti-spike IgG GMFRs in PLWH and HIV-uninfected participants, respectively, were 12·4 and 12·9 (D35) and 12·2 and 13·6 (D84). Comparable outcomes occurred across dosing regimens and in well-controlled and less–well-controlled PLWH. Microneutralization GMFRs at D84 in PLWH and HIV-uninfected participants, respectively, were: 6·9 and 10·1 (2-DoseD0/D21), 11·0 and 11·3 (2-DoseD0/D70), and 17·2 (PLWH 3-Dose). Antibody responses against BA.1 trended similar to those against the ancestral virus. Safety outcomes were comparable among PLWH and HIV-uninfected participants. ConclusionThis study demonstrated that NVX-CoV2373 produced consistent immunogenicity responses to SARS-CoV-2 among PLWH and HIV-uninfected participants, with no new safety signals. FundingNovavax, Inc.

Neutralizing Antibody Immune Correlates for a Recombinant Protein Vaccine in the COVAIL Trial.

For COVAIL recipients of a COVID-19 Sanofi booster vaccine, neutralizing antibody titers were assessed as a correlate of risk (CoR) of COVID-19. Peak and exposure-proximal titers were inverse CoRs with covariate-adjusted hazard ratios (95% confidence intervals) 0.30 (0.11, 0.78) and 0.25 (0.07, 0.85) per 10-fold increase in weighted average titer.

Dual-antigen fusion protein vaccination induces protective immunity against Candida albicans infection in mice

ABSTRACT Candida albicans Is a leading cause of nosocomial bloodstream infections, particularly in immunocompromised patients. Current therapeutic strategies are insufficient, highlighting the need for effective vaccines. This study aimed to evaluate the efficacy of a dual-antigen fusion protein vaccine (AH) targeting the Als3 and Hyr1 proteins of C. albicans, using AlPO4 as an adjuvant. The AH vaccine was constructed by fusing Als317-432 and Hyr125-350 proteins, and its immunogenicity was tested in BALB/c mice and New Zealand white rabbits. Mice received three intramuscular doses of the vaccine combined with AlPO4, followed by a lethal challenge with C. albicans SC5314. Survival rates, antibody responses, cytokine production, fungal burdens, and organ pathology were assessed. The vaccine’s efficacy was also validated using rabbit serum. Mice vaccinated with the AH-AlPO4 combination exhibited significantly higher antibody titers, particularly IgG and its subclasses, compared to controls (p < .001). The survival rate of vaccinated mice was 80% post-infection, significantly higher than the control group (p < .01). Vaccinated mice showed reduced fungal loads in the blood, kidneys, spleen, and liver (p < .05). Increased levels of interferon gamma and interleukin (IL)-17A were observed, indicating robust T helper (Th) 1 and Th17 cell responses. Vaccination mitigated organ damage, with kidney and liver pathology scores significantly lower than those of unvaccinated mice (p < .05). Rabbit serum with polyclonal antibodies demonstrated effective antifungal activity, confirming vaccine efficacy across species. The AH-AlPO4 vaccine effectively induced strong immune responses, reduced fungal burden, and protected against organ pathology in C. albicans infections. These findings support further development of dual-antigen vaccine strategies.

Immunity and Protective Efficacy of a Plant-Based Tobacco Mosaic Virus-like Nanoparticle Vaccine against Influenza a Virus in Mice.

The rapid production of influenza vaccines is crucial to meet increasing pandemic response demands. Here, we developed plant-made vaccines comprising centralized consensus influenza hemagglutinin (HA-con) proteins (H1 and H3 subtypes) conjugated to a modified plant virus, tobacco mosaic virus (TMV) nanoparticle (TMV-HA-con). We compared immune responses and protective efficacy against historical H1 or H3 influenza A virus infections among TMV-HA-con, HA-con protein combined with AddaVax™ adjuvant, and whole-inactivated virus vaccine (Fluzone®). Immunogenicity studies demonstrated robust IgG, IgM, and IgA responses in the TMV-HA-con and HA-con protein vaccinated groups, with relatively low induction of interferon (IFN)-γ+ T-cell responses across all vaccinated groups. The TMV-HA-con and HA-con protein groups displayed partial protection (100% and 80% survival) with minimal weight loss following challenge with two H1N1 strains. The HA-con protein group exhibited 80% and 100% survival against two H3 strains, whereas the TMV-HA-con groups showed reduced protection (20% survival). The Fluzone® group conferred 20-100% survival against two H1N1 strains and one H3N1 strain, but did not protect against H3N2 infection. Our findings indicate that TMV-HA and HA-con protein vaccines with adjuvant induce protective immune responses against influenza A virus infections. Furthermore, our results underscore the potential of plant-based production using TMV-like nanoparticles for developing influenza A virus candidate vaccines.

The social shaping of biotechnological innovation. The case of Covid-19 protein vaccine in Cuba and the US

AbstractLike other technologies, vaccines are socially shaped by socio-economic, political and organisational factors. Property rights, value capture strategies and public innovation policies guide research teams in the biochemical design of vaccines, with inevitable consequences for their price and accessibility. The Covid-19 pandemic provided an opportunity to analyse this institutional shaping process and its consequences for global public health from a political economy perspective. Indeed, the same type of invention, a recombinant protein vaccine, was simultaneously and originally developed in the US and Cuban biopharmaceutical industries and in the field of philanthropic Open Innovation. The article shows, through empirical research that collected direct testimony from scientists and privileged observers of the vaccine development fields, how certain norms and values characteristic of the US industry (financialization, assetization and de-risk) created a path dependency in the use of proprietary and experimental biotechnologies that made the US vaccine Nuvaxovid more expensive and complex to produce, but no more effective and safe than Abdala, Soberana 02 and Corbevax. In addition, the institutional constraints of the US biopharmaceutical industry on radical innovation, even within a mature biotechnology platform such as protein vaccines, would have resulted in a competitive disadvantage for Nuvaxovid, which was as expensive as an mRNA vaccine but less rapid to market and less reliable in delivery. The case of protein vaccines against Covid-19 thus shows how the institutional architectures of techno-scientific capitalism create not only inequalities but also inefficiencies, and that an innovation path with excellent results is possible even in competition where the market is not the dominant order of worth.

Label-Free Quantitative Proteomics Analysis of COVID-19 Vaccines by Nano LC-HRMS.

A nanoliter liquid chromatography-high resolution mass spectrometry-based method was developed for quantitative proteomics analysis of COVID-19 vaccines. It can be used for simultaneous qualitative and quantitative analysis of target proteins and host cell proteins (HCPs) in vaccine samples. This approach can directly provide protein information at the molecular level. Based on this, the proteomes of 15 batches of COVID-19 inactivated vaccine samples from two companies and 12 batches of COVID-19 recombinant protein vaccine samples from one company were successfully analyzed, which provided a significant amount of valuable information. Samples produced in different batches or by different companies can be systematically contrasted in this way, offering powerful supplements for existing quality standards. This strategy paves the way for profiling proteomics in complex samples and provides a novel perspective on the quality evaluation of bio-macromolecular drugs.

Immunogenicity and safety of different dose levels of Ad26.RSV.preF/RSV preF protein vaccine in adults aged 60 years and older: A randomized, double-blind, placebo-controlled, phase 2a study

BackgroundRespiratory syncytial virus (RSV) can cause severe illness in older adults. A combination vaccine containing Ad26.RSV.preF and purified recombinant RSV preF protein has previously demonstrated efficacy and tolerability in older adults. We report results of a dose-ranging study to determine immunogenicity and safety of different doses of the Ad26.RSV.preF component in the combined Ad26.RSV.preF/RSV preF protein vaccine to support Ad26.RSV.preF drug product release and stability specifications. MethodsIn this randomized, double-blind, placebo-controlled, phase 2a study, adults aged ≥60 years in good or stable health were randomly assigned within 1 of 3 cohorts to receive either placebo or Ad26.RSV.preF/RSV preF protein, composed of different doses of Ad26.RSV.preF with a fixed dose of RSV preF protein (150 μg). Ad26.RSV.preF doses in Cohort 1 (4 dose-down groups) ranged from 3.7 × 109 to 1.0 × 1011 viral particles (vp). Doses in Cohorts 2 and 3 (2 dose-up groups, each) ranged from 1.0 to 1.6 × 1011 vp. Primary endpoints were immunogenicity (RSV preF protein antibody titers) for Cohort 1 and safety (solicited local and systemic adverse events [AEs] and unsolicited AEs) for Cohorts 2 and 3. Immunogenicity analyses (RSV preF protein antibody titers, RSV A2 neutralizing antibodies, and RSV-F–specific interferon-γ enzyme-linked immunosorbent spot) were performed on the day of vaccination and 14 days, 3 months, and 6 months postvaccination. Safety was monitored from vaccination until study end. ResultsOverall, 454 participants were enrolled and received 1 dose of study vaccine or placebo (Cohort 1, n = 226; Cohort 2, n = 124; Cohort 3, n = 104). No substantial differences in measured immune responses were observed between lower or higher Ad26.RSV.preF doses compared with Ad26.RSV.preF 1.0 × 1011 vp across all postvaccination time points. All Ad26.RSV.preF doses between 3.7 × 109 vp and 1.6 × 1011 vp were well tolerated, with no safety issues identified. ConclusionsResults of this dose-ranging study may be used to inform the refinement of Ad26.RSV.preF drug product release and stability specifications.Clinical Trial Registration:ClinicalTrials.gov Identifier: NCT04453202

Seno-antigen-pulsed dendritic cell vaccine induce anti-aging immunity to improve adipose tissue senescence and metabolic abnormalities

Anti-aging immunity induced by vaccines was recently reported to enable the elimination of senescent cells. However, the initial immune response to vaccination declines with age, and there is evidence that elderly dendritic cells (DCs) have a reduced capacity to stimulate T cells. Identification of alternative anti-aging vaccine is therefore warranted. Here, we developed a DC vaccine that delivers a cationic protein (CP) fused with the seno-antigen peptides Gpnmb (Gpnmb-CP) into DCs. The Gpnmb-CP-pulsed DC vaccine (Gpnmb-CP-DC) efficiently presented antigens and activated CD8+ T cells, leading to enhanced immune cytotoxicity and memory responses in CD8+ T cells. Thus, the targeted anti-aging immunity triggered by Gpnmb-CP-DC has the ability to selectively eliminate senescent adipocytes and effectively improve age-related metabolic abnormalities in both high-fat diet (HFD)-induced young and aged mice models, as well as in natural aging mouse model. In contrast, the Gpnmb-CP protein vaccine exhibits minimal efficacy in aged mice model. Furthermore, we observed a decreased phagocytic capacity for antigens in aging DCs, accompanied by an upregulation of the immune checkpoint PDL1 expression and a noticeable decline in activated CD8+ T cell. Hence, Gpnmb-CP-DC emerges as a promising vaccine candidate, demonstrating the capacity to induce potent anti-aging immunity, mitigating adipose tissue senescence and metabolic abnormalities, while resilient to the senescent environment of the organism.

Diverse BCR usage and T cell activation induced by different COVID-19 sequential vaccinations.

Using the same laboratory test to avoid unnecessary interference due to cohort ethnicity, and experimental and statistical errors, we have compared the T/B cell immune response in the same cohort sequential vaccinated by different types of COVID-19 vaccine. We found that different sequential vaccinations can induce different dominant BCR usage with no significant neutralizing titers and RBD+ B-cell phenotype. Recombinant protein vaccine can induce higher numbers of regulatory T cells, circulating TFH (CTFH)1, CTFH17, and CTFH-CM, and lower SMNE+ T-cell proliferative capacity than the other two groups, whereas I-I-A showed higher proportion and number of virus-specific CD4+ T cells than I-I-R. Overall, our study provides a deep insight about the source of differences in immune protection of different types of COVID-19 vaccines, which further improves our understanding of the mechanisms underlying the immune response to SARS-CoV-2.

Thermal Stabilisation of Lysozyme through Ensilication.

Protein therapeutics, vaccines, and other commercial products are often sensitive to environmental factors, such as temperature and long-term storage. In many cases, long-term protein stability is achieved by refrigeration or freezing. One alternative is the encapsulation of the protein cargo within an inert silica matrix (ensilication) and storage or transport at room temperature as a dry powder. In this paper, we test the effect of three commonly used biological buffers on the ensilication, storage, and desilication of the enzyme lysozyme. We show that ensilication protects lysozyme from heat (100 °C for 1 h) and during storage (18 months at room temperature). The choice of ensilication buffer has little effect on the activity of lysozyme after desilication. Our results provide confidence in the continued pursuit of ensilication as a methodology for protein stabilisation and in its compatibility with biological buffers.