Split Vaccine Research Articles

The cationic liposome CCS/C adjuvant induces immunity to influenza independently of the adaptor protein MyD88

ABSTRACT Traditional non-living vaccines are often least effective in the populations that need them most, such as neonates and elderly adults. Vaccine adjuvants are one approach to boost the immunogenicity of antigens in populations with reduced immunity. Ideally, vaccine adjuvants will increase the seroconversion rates across the population, lead to stronger immune responses, and enable the administration of fewer vaccine doses. We previously demonstrated that a cationic liposomal formulation of the commercial influenza split virus vaccine (CCS/C-HA) enhanced cellular and humoral immunity to the virus, increased seroconversion rates, and improved survival after live virus challenge in a preclinical model, as compared to the commercial vaccine as is (F-HA). We now evaluated vaccine efficacy in different strains and sexes of mice and determined the role of innate immunity in the mechanism of action of the CCS/C adjuvant by testing the response of mice deficient in Toll-like receptors or the TLR/IL-1 adaptor protein MyD88 following immunization with CCS/C-HA vs. F-HA. Although TLR2- and TLR4-deficient mice responded to F-HA immunization, F-HA immunization failed to engender a significant immune response in the absence of MyD88. In contrast, immunization with the CCS/C-HA vaccine overcame the requirement for MyD88 in the response to the commercial vaccine and improved the immune responses and seroconversion rates in all strains of mice tested, including those deficient in TLR2 and TLR4.

H7N9 influenza split vaccine with SWE oil-in-water adjuvant greatly enhances cross-reactive humoral immunity and protection against severe pneumonia in ferrets

Until universal influenza vaccines become available, pandemic preparedness should include developing classical vaccines against potential pandemic influenza subtypes. We here show that addition of SWE adjuvant, a squalene-in-water emulsion, to H7N9 split influenza vaccine clearly enhanced functional antibody responses in ferrets. These were cross-reactive against H7N9 strains from different lineages and newly emerged H7N9 variants. Both vaccine formulations protected in almost all cases against severe pneumonia induced by intratracheal infection of ferrets with H7N9 influenza; however, the SWE adjuvant enhanced protection against virus replication and disease. Correlation analysis and curve fitting showed that both VN- and NI-titers were better predictors for protection than HI-titers. Moreover, we show that novel algorithms can assist in better interpretation of large data sets generated in preclinical studies. Cluster analysis showed that the adjuvanted vaccine results in robust immunity and protection, whereas the response to the non-adjuvanted vaccine is heterogeneous, such that the protection balance may be more easily tipped toward severe disease. Finally, cluster analysis indicated that the dose-sparing capacity of the adjuvant is at least a factor six, which greatly increases vaccine availability in a pandemic situation.

Immune Response and Protective Efficacy of Inactivated and Live Influenza Vaccines Against Homologous and Heterosubtypic Challenge.

Inactivated (whole-virion, split, subunit, and adjuvanted) vaccines and live attenuated vaccine were tested in parallel to compare their immunogenicity and protective efficacy. Homologous and heterosubtypic protection against the challenge with influenza H5N1 and H1N1 viruses in a mouse model were studied. Single immunization with live or inactivated whole-virion H5N1 vaccine elicited a high level of serum antibodies and provided complete protection against the challenge with the lethal A/Chicken/Kurgan/3/05 (H5N1) virus, whereas application of a single dose of the split vaccine was much less effective. Adjuvants increased the antibody levels. Addition of the Iso-SANP adjuvant to the split vaccine led to a paradoxical outcome: it increased the antibody levels but reduced the protective effect of the vaccine. All tested adjuvants shifted the ratio between IgG1 and IgG2a antibodies. Immunization with any of the tested heterosubtypic live viruses provided partial protection against the H5N1 challenge and significantly reduced mouse mortality, while inactivated H1N1 vaccine offered no protection at all. More severe course of illness and earlier death were observed in mice after immunization with adjuvanted subunit vaccines followed by the challenge with the heterosubtypic virus compared to challenged unvaccinated animals.

Recombinant Measles AIK-C Vaccine Strain Expressing Influenza HA Protein.

Recombinant measles AIK-C vaccine expressing the hemagglutinin (HA) protein of influenza A/Sapporo/107/2013(H1N1pdm) (MVAIK/PdmHA) was constructed. Measles particle agglutination (PA) and influenza hemagglutinin inhibition (HI) antibodies were induced in cotton rats immunized with MVAIK/PdmHA. Cotton rats immunized with two doses of the HA split vaccine were used as positive controls, and higher HI antibodies were detected 3 weeks after the first dose. Following the challenge of A/California/07/2009(H1N1pdm), higher viral loads (107 TCID50/g) were detected in the lung homogenates of cotton rats immunized with the empty vector (MVAIK) or control groups than those immunized with MVAIK/Pdm HA (103 TCID50/g) or the group immunized with HA split vaccine (105 TCID50/g). Histopathologically, destruction of the alveolar structure, swelling of broncho-epithelial cells, and thickening of the alveolar wall with infiltration of inflammatory cells and HA antigens were detected in lung tissues obtained from non-immunized rats and those immunized with the empty vector after the challenge, but not in those immunized with the HA spilt or MVAIK/PdmHA vaccine. Lower levels of IFN-α, IL-1β, and TNF-α mRNA, and higher levels of IFN-γ mRNA were found in the lung homogenates of the MVAIK/PdmHA group. Higher levels of IFN-γ mRNA were detected in spleen cell culture from the MVAIK/PdmHA group stimulated with UV-inactivated A/California/07/2009(H1N1pdm). In conclusion, the recombinant MVAIK vaccine expressing influenza HA protein induced protective immune responses in cotton rats.

IL-33 Is Essential for Adjuvant Effect of Hydroxypropyl-β-Cyclodexrin on the Protective Intranasal Influenza Vaccination.

Vaccine adjuvants are traditionally used to augment and modulate the immunogenicity of vaccines, although in many cases it is unclear which specific molecules contribute to their stimulatory activity. We previously reported that both subcutaneous and intranasal administration of hydroxypropyl-β-cyclodextrin (HP-β-CD), a pharmaceutical excipient widely used to improve solubility, can act as an effective adjuvant for an influenza vaccine. However, the mechanisms by which mucosal immune pathway is critical for the intranasal adjuvant activity of HP-β-CD have not been fully delineated. Here, we show that intranasally administered HP-β-CD elicits a temporary release of IL-33 from alveolar epithelial type 2 cells in the lung; notably, IL-33 expression in these cells is not stimulated following the use of other vaccine adjuvants. The experiments using gene deficient mice suggested that IL-33/ST2 signaling is solely responsible for the adjuvant effect of HP-β-CD when it is administered intranasally. In contrast, the subcutaneous injection of HP-β-CD and the intranasal administration of alum, as a damage-associated molecular patterns (DAMPs)-inducing adjuvant, or cholera toxin, as a mucosal adjuvant, enhanced humoral immunity in an IL-33-independent manner, suggesting that the IL-33/ST2 pathway is unique to the adjuvanticity of intranasally administered HP-β-CD. Furthermore, the release of IL-33 was involved in the protective immunity against influenza virus infection which is induced by the intranasal administration of HP-β-CD-adjuvanted influenza split vaccine. In conclusion, our results suggest that an understanding of administration route- and tissue-specific immune responses is crucial for the design of unique vaccine adjuvants.

O/W Nanoemulsion as an Adjuvant for an Inactivated H3N2 Influenza Vaccine: Based on Particle Properties and Mode of Carrying.

Background and PurposeAdjuvant can reduce vaccine dosage and acquire better immune protection to the body, which helps to deal with the frequent outbreaks of influenza. Nanoemulsion adjuvants have been proved efficient, but the relationship between their key properties and the controlled release which greatly affects immune response is still unclear. The present work explores the role of factors such as particle size, the polydispersity index (PDI), stability and the safety of nanoemulsions by optimizing the water concentration, oil phase and modes of carrying, to explain the impact of those key factors above on adjuvant effect.MethodsIsopropyl myristate (IPM), white oil, soybean oil, and grape-kernel oil were chosen as the oil phase to explore their roles in emulsion characteristics and the adjuvant effect. ICR mice were immunized with an emulsion-inactivated H3N2 split influenza vaccine mixture, to compare the nanoemulsion’s adjuvant with traditional aluminium hydroxide or complete Freund’s adjuvant.ResultsParticle size of all the nanoemulsion formed in our experiment ranged from 20 nm to 200 nm and did not change much when diluted with water, while the PDI decreased obviously, indicating that the particles tended to become more dispersive. Formulas with 80% or 85.6% water concentration showed significant higher HAI titer than aluminium hydroxide or complete Freund’s adjuvant, and adsorption rather than capsule mode showed higher antigen delivery efficiency. As mentioned about oil phase, G (IPM), F (white oil), H (soybean oil), and I (grape-kernel oil) showed a decreasing trend in their adjuvant efficiency, and nanoemulsion G was the best adjuvant with smaller and uniform particle size.ConclusionEmulsions with a smaller, uniform particle size had a better adjuvant effect, and the adsorption mode was generally more efficient than the capsule mode. The potential adjuvant order of the different oils was as follows: IPM > white oil > soybean oil > grape-kernel oil.

Chimeric hemagglutinin supra-seasonal universal influenza vaccine candidates administered sequentially by the intramuscular route are locally and systemically well-tolerated in rabbits

Sequential intramuscular immunization with chimeric hemagglutinins (cHA) composed of the same conserved HA stalk domain and distinct HA heads is a proposed strategy to produce a supra-seasonal universal influenza vaccine. To evaluate the local tolerance and the local and systemic effects of this strategy, two studies were performed in rabbits. In the first study, two different split virion monovalent cHA vaccines, containing cH5/1N1 and cH8/1N1, with or without AS01 or AS03, were injected at a two-week interval. In the second study, animals were given these vaccines and two weeks later an additional dose of split virion monovalent cHA vaccine containing cH11/1N1, with or without AS01 or AS03. General health status, rectal temperature, local tolerance, ophthalmology, hematology, coagulation, and blood chemistry parameters were monitored. Macroscopic and microscopic evaluations were performed three days after the last dose and after a treatment-free recovery period. The treatment-related changes included body weight loss and food consumption decrease, increases in neutrophil count, C-reactive protein and fibrinogen levels. Microscopic signs of inflammation at the injection sites and immune stimulation of the draining lymph nodes and spleen were also noticed. Most post-injection findings could be linked to the transient inflammation due to the establishment of the desired vaccine-elicited immune response, and were mainly observed in the adjuvanted groups. In conclusion, the sequential administration of different cHA vaccines was locally and systemically well-tolerated in rabbits.

Intranasal Immunization Using CTA1-DD as a Mucosal Adjuvant for an Inactivated Influenza Vaccine

ObjectiveTo evaluate the effect of intranasal immunization with CTA1-DD as mucosal adjuvant combined with H3N2 split vaccine. MethodsMice were immunized intranasally with PBS (negative control), or H3N2 split vaccine (3 μg/mouse) alone, or CTA1-DD (5 μg/mouse) alone, or H3N2 split vaccine (3 μg/mouse) plus CTA1-DD (5 μg/mouse). Positive control mice were immunized intramuscularly with H3N2 split vaccine (3 μg/mouse) and alum adjuvant. All the mice were immunized twice, two weeks apart. Then sera and mucosal lavages were collected. The specific HI titers, IgM, IgG, IgA, and IgG subtypes were examined by ELISA. IFN-γ and IL-4 were test by ELISpot. In addition, two weeks after the last immunization, surivival after H3N2 virus lethal challenge was measured. ResultsH3N2 split vaccine formulated with CTA1-DD could elicit higher IgM, IgG and hemagglutination inhibition titers in sera. Furthermore, using CTA1-DD as adjuvant significantly improved mucosal secretory IgA titers in bronchoalveolar lavages and vaginal lavages. Meanwhile this mucosal adjuvant could enhance Th-1-type responses and induce protective hemagglutination inhibition titers. Notably, the addition of CTA1-DD to split vaccine provided 100% protection against lethal infection by the H3N2 virus. ConclusionCTA1-DD could promote mucosal, humoral and cell-mediated immune responses, which supports the further development of CTA1-DD as a mucosal adjuvant for mucosal vaccines.

Lipid Nanoparticles Potentiate CpG-Oligodeoxynucleotide-Based Vaccine for Influenza Virus

Current influenza vaccines are generally effective against highly similar (homologous) strains, but their effectiveness decreases markedly against antigenically mismatched (heterologous) strains. One way of developing a universal influenza vaccine with a broader spectrum of protection is to use appropriate vaccine adjuvants to improve a vaccine's effectiveness and change its immune properties. Oligodeoxynucleotides (ODNs) with unmethylated cytosine-phosphate-guanine (CpG) motifs (CpG ODNs), which are Toll-like-receptor 9 (TLR9) agonists, are among the most promising adjuvants and are already being used in humans. However, the development of novel delivery vehicles to improve adjuvant effects in vivo is highly desirable. Here, we assessed the potential of lipid nanoparticles (LNPs) as CpG ODN delivery vehicles in mice to augment the vaccine adjuvant effects of CpG ODN and enhance the protective spectrum of conventional influenza split vaccine (SV). In vitro, compared with CpG ODN, LNPs containing CpG ODNs (LNP-CpGs) induced significantly greater production of cytokines such as IL-12 p40 and IFN-α by mouse dendritic cells (DCs) and significantly greater expression of the co-stimulatory molecules CD80 and CD86 on DCs. In addition, after subcutaneous administration in mice, compared with CpG ODN, LNP-CpGs enhanced the expression of CD80 and CD86 on plasmacytoid DCs in draining lymph nodes. LNP-CpGs given with SV from H1N1 influenza A virus improved T-cell responses and gave a stronger not only SV-specific but also heterologous-virus-strain-specific IgG2c response than CpG ODN. Furthermore, immunization with SV plus LNP-CpGs protected against not only homologous strain challenge but also heterologous and heterosubtypic strain challenge, whereas immunization with SV plus CpG ODNs protected against homologous strain challenge only. We therefore demonstrated that LNP-CpGs improved the adjuvant effects of CpG ODN and broadened the protective spectrum of SV against influenza virus. We expect that this strategy will be useful in developing adjuvant delivery vehicles and universal influenza vaccines.

Safety and immunogenicity of a seasonal trivalent inactivated split influenza vaccine: a double blind, phase III randomized clinical trial in healthy Serbian adults.

This study was a phase III, multicenter, double-blind, randomized, placebo-controlled trial to evaluate the safety and immunogenicity of a seasonal trivalent split, inactivated influenza vaccine (TIV) in healthy Serbian adults between the ages of 18 and 65 years. This egg-based vaccine was manufactured by the Institute of Virology, Vaccines and Sera, Torlak, Belgrade, Serbia. A total of 480 participants were assigned randomly in a ratio of 2:1 to receive a single intramuscular dose (0.5 ml) of the vaccine (15 µg of hemagglutinin per strain) or placebo (phosphate-buffered saline). Participants were monitored for safety, including solicited and unsolicited adverse events (AEs) and serious adverse events (SAEs). No SAEs related to vaccination were reported. Injection site pain (51.3%), injection site tenderness (40.4%), tiredness (17.0%), and headache (15.1%) were the most commonly reported solicited events in the vaccine group. Incidence of related unsolicited AEs was low (1.3%) among vaccinees. Hemagglutinin inhibition (HAI) titers were measured before and 21 days after vaccination in 151 participants. Overall, HAI seroconversion rates to H1 and H3 were observed in 90.1% and 76.2% of vaccinees, respectively. For B antigen, it was 51.5%, likely due to high pre-vaccination titers. Post-vaccination seroprotection rates were in the range of 78.2–95.0% for the three antigens. Post-vaccination geometric mean titers (GMT) were at least 3.8 times higher than baseline levels for all the three strains among vaccinees. Overall, the study showed that the vaccine was safe and well tolerated, and induced a robust immune response against all three vaccine strains.ClinicalTrials.gov identifier: NCT02935192, October 17, 2016

Surveillance on the Immune Effectiveness of Quadrivalent andTrivalent Split Influenza Vaccines - Shenzhen Cityand Changzhou City, China, 2018-2019.

What is already known about this topic? Vaccinations are the most effective way to prevent influenza virus infections and severe outcomes. Influenza vaccine effectiveness can vary by seasons. What is added by this report? This report monitors the antibody level among the population over time after administration of the quadrivalent or trivalent split influenza vaccine. What are the implications for public health practice? Real-time monitoring of serum antibody changes after vaccination provides important data for the development of reasonable and effective strategies for influenza prevention and control.

Long-lasting protective immunity against H7N9 infection is induced by intramuscular or CpG-adjuvanted intranasal immunization with the split H7N9 vaccine

There is an urgent need for efficient vaccines against the highly pathogenic avian influenza A viral strain H7N9. The duration and intensity of the immune response to H7N9 critically impacts the epidemiology of influenza viral infection at the population level. However, the insufficient immunogenicity of H7N9 raises concerns about vaccine efficacy. In this study, we evaluated the impact of immunization routes and the adjuvant CpG on the immune response to a split H7N9 vaccine in mice. Determination of humoral and cellular responses to the vaccine revealed that after four vaccine doses, high titers of H7N9-specific serum IgG, determined by the influenza hemagglutination inhibition (HI) assay, were induced through the intramuscular (i.m.) route and lasted for at least 40 weeks. CpG-adjuvanted immunization increased the levels of long-lived IFN-γ+ T cells and raised the Th1-biased IgG2a/IgG1 response ratio. In addition, aside from mucosal IgA, CpG-adjuvanted intranasal (i.n.) immunization elicited serum IgG and cellular responses of a similar duration and intensity to CpG-adjuvanted i.m. immunization. Mouse challenge assays demonstrated that 24 weeks following i.m. immunization without CpG or CpG-adjuvanted immunization through the i.m. or i.n. routes, both offered a high level of protection against H7N9 infection. These results indicate that efficient long-term protection against H7N9 can be achieved via the optimization of vaccination strategies, such as immunization doses, routes, and adjuvants.

Nano-emulsion as a vaccine adjuvant can enhance the humoral immunity against influenza in aged and young mice

Objective To evaluate the immunogenicity of split influenza H1N1 vaccine formulated with an oil-in-water nano-emulsion adjuvant in aged mice and young mice. Methods A nano-emulsion adjuvant formulated split influenza H1N1 vaccine was used to immunize aged and young mice through intramuscular injection. Each mouse was immunized with 0.012 μg of hemagglutinin (HA) twice with an interval of 28 d. Hemagglutination inhibition (HI) titers in serum were measured 27 d after first immunization. Serum HI, IgG1 and IgG2a titers were detected 14 d after the last immunization. No adjuvant-formulated vaccine and normal saline (NS) were used to set up control groups. Virus challenge test was carried out using 10 times the median lethal dose (LD50) of A/Puerto Rico/8/34 (H1N1) strain two weeks after the last immunization and the protective effects were assessed through measuring the dynamic changes in body weight and survival rate. Results Higher levels of serum HI, IgG1 and IgG2a antibodies and higher HI antibody conversion rates were induced in the adjuvant groups, especially in the aged mice group, than in the control groups. Nano-emulsion adjuvant improved the immunogenicity of HA and mouse immunity to A/Puerto Rico/8/34 (H1N1). Conclusions Nano-emulsion adjuvant could enhance the immunogenicity of influenza antigens, especially in aged mice. Key words: Adjuvant; Influenza; Nano-emulsion adjuvant; Aged mice; Immunogenicity

Vaccine Efficacy Induced by 2009 Pandemic H1N1 Virus-Like Particles Differs from that Induced by Split Influenza Virus

ABSTRACT Influenza virus-like particles (VLPs) vaccines are highly immunogenic, showing strong protective efficacy against homologous virus infection compared to split vaccine. However, a comparative efficacy study against heterosubtypic virus infection between VLPs and split vaccine has yet to been reported. In this study, we generated VLPs vaccine containing hemagglutinin (HA) and matrix protein (M1) of the 2009 pandemic H1N1, and investigated the protective efficacies induced by VLPs vaccine and commercial monovalent H1N1 pandemic split vaccine from Sanofi-Pasteur. Mice were intramuscularly immunized with either VLPs vaccine or split vaccine and subsequently challenge-infected with homologous virus (A/California/04/2009, H1N1) or heterosubtypic virus (A/Philippines/82, H3N2) after 4.5 months. VLPs vaccination demonstrated a higher level of protective efficacy against homologous viruses compared to split vaccine, as lessened lung viral loads and minuscule levels of proinflammatory lung cytokines IFN-gamma and IL-6 were observed. Protective efficacies were close to non-existent in VLP-immunized mice challenged with heterosubtypic viruses (H3N2). In contrast, split vaccine showed lower vaccine efficacy against homologous virus than VLP vaccine, but conferred better protection against heterosubtypic viruses through lung viral loads reduction and heightened survival rate. These results indicate that influenza VLPs provide better protective efficacy against homologous virus challenge infection, whereas split vaccine shows better protective efficacy against heterosubtypic virus challenge. Findings from the current study contribute to the rational design of vaccines conferring a broad range of protection.

A PBMC-Based System to Assess Human T Cell Responses to Influenza Vaccine Candidates In Vitro.

Vaccine development is an expensive and time-consuming process that heavily relies on animal models. Yet, vaccine candidates that have previously succeeded in animal experiments often fail in clinical trials questioning the predictive value of animal models. Alternative assay systems that can add to the screening and evaluation of functional characteristics of vaccines in a human context before embarking on costly clinical trials are therefore urgently needed. In this study, we have established an in vitro system consisting of long-term cultures of unfractionated peripheral blood mononuclear cells (PBMCs) from healthy volunteers to assess (recall) T cell responses to vaccine candidates. We observed that different types of influenza vaccines (whole inactivated virus (WIV), split, and peptide vaccines) were all able to stimulate CD4 and CD8 T cell responses but to different extents in line with their reported in vivo properties. In-depth analyses of different T cell subsets revealed that the tested vaccines evoked mainly recall responses as indicated by the fact that the vast majority of the responding T cells had a memory phenotype. Furthermore, we observed vaccine-induced activation of T follicular helper cells, which are associated with the induction of humoral immune responses. Our results demonstrate the suitability of the established PBMC-based system for the in vitro evaluation of memory T cell responses to vaccines and the comparison of vaccine candidates in a human immune cell context. As such, it can help to bridge the gap between animal experiments and clinical trials and assist in the selection of promising vaccine candidates, at least for recall antigens.

Changes of urine metabolite profiles are induced by inactivated influenza vaccine inoculations in mice

The safety evaluation of vaccines is critical to avoid the development of side effects in humans. To increase the sensitivity of detection for toxicity tests, it is important to capture not only pathological changes but also physiological changes. 1H nuclear magnetic resonance (NMR) spectroscopy analysis of biofluids produces profiles that show characteristic responses to changes in physiological status. In this study, mouse urine metabolomics analysis with 1H NMR was performed using different influenza vaccines of varying toxicity to assess the usefulness of 1H NMR in evaluating vaccine toxicity. Two types of influenza vaccines were used as model vaccines: a toxicity reference vaccine (RE) and a hemagglutinin split vaccine. According to the blood biochemical analyses, the plasma alanine transaminase levels were increased in RE-treated mice. Changes in metabolite levels between mice administered different types of influenza vaccines were observed in the 1H NMR spectra of urine, and a tendency toward dosage-dependent responses for some spectra was observed. Hierarchical clustering analyses and principal component analyses showed that the changes in various urine metabolite levels allowed for the classification of different types of vaccines. Among them, two liver-derived metabolites were shown to largely contribute to the formation of the cluster. These results demonstrate the possibility that urine metabolomics analysis could provide information about vaccine-induced toxicity and physiological changes.

Prime-pull vaccination with a plant-derived virus-like particle influenza vaccine elicits a broad immune response and protects aged mice from death and frailty after challenge

BackgroundAdministered intramuscularly (IM), plant-derived, virus-like-particle (VLP) vaccines based on the influenza hemagglutinin (HA) protein elicit both humoral and cellular responses that can protect aged mice from lethal challenge. Unlike split virus vaccines, VLPs can be administered by different routes including intranasally (IN). We evaluated novel vaccine strategies such as prime-pull (IM boosted by IN) and multi-modality vaccination (IM and IN given simultaneously). We wished to determine if these approaches would provide better quality protection in old mice after less severe (borderline-lethal) challenge (ie: immunogenicity, frailty and survival).ResultsSurvival rates were similar in all vaccinated groups. Antibody responses were modest in all groups but tended to be higher in VLP groups compared to inactivated influenza vaccine (IIV) recipients. All VLP groups had higher splenocyte T cell responses than the split virus group. Lung homogenate chemokine/cytokine levels and virus loads were lower in the VLP groups compared to IIV recipients 3 days after challenge (p < 0.05 for viral load vs all VLP groups combined). The VLP-vaccinated groups also had less weight loss and recovered more rapidly than the IIV recipients. There was limited evidence of an immunologic or survival advantage with IN delivery of the VLP vaccine.ConclusionCompared to IIV, the plant-derived VLP vaccine induced a broader immune response in aged mice (cellular and humoral) using either traditional (IM/IM) or novel schedules (multi-modality, prime-pull).

Modulating effects of a decoction of a traditional Japanese herbal formula, hochuekkito (with Hedysari radix and Atractylodis rhizoma), on the local mucosal immune system of aged mice

ABSTRACTAimHochuekkito is generally considered to express its clinical effects through modulation of the immune system. The formula using Hedysari radix and Atractylodis rhizoma as the component herbs, also has been used clinically as hochuekkito, but its immunopharmacological activity has not been clarified.MethodsDecocted extracts (0.1, 0.5 and 1.0 g/kg) were given to BALB/c mice intranasally immunized with influenza split vaccine, and influenza virus‐specific antibody titers were measured on ELISA together with transcriptome analyses with mRNA from uterus and lung.ResultsHochuekkito at lower doses (0.1 and 0.5 g/kg) increased influenza virus‐specific antibody titers in nasal washes, bronchoalveolar fluid (BALF), genital washes and feces. The higher dose (1 g/kg) of the extract, however, did not induce further increase of the antibody titer in BALF and genital washes. Furthermore, the extract inversely decreased the antibody titers in sera dose dependently. On transcriptome analysis, the 1 g/kg extract upregulated mRNA expression of co‐inhibitory receptors Pd‐1 and Lag3 in uterus but not in the lung. Meanwhile, the extract induced upregulation of the mRNA expression of marker molecules (CD163 and galectin‐1) related to M2 macrophages in lung.ConclusionsHochuekkito with Hedysari radix and Atractylodis rhizoma modulates systemic and local mucosal immune systems in different ways. The formula encourages induction and recruitment of regulatory T lymphocytes and M2 macrophages in genital tract and lung, respectively, at the higher dose.

Novel calixarene-based surfactant enables low dose split inactivated vaccine protection against influenza infection

Influenza A viruses cause major morbidity and represent a severe global health problem. Current influenza vaccines are mainly egg-based products requiring the split of whole viruses using classical detergents such as Triton X-100, which implies certain limitations. Here, we report the use of the novel calixarene-based surfactant CALX133ACE as an alternative to classical detergents for influenza inactivated split vaccine preparation. We confirmed that CALX133ACE-based split HA antigens are fully functional and quantifiable by the “gold standard” method SRID. Additionally, as in the case of the Triton X-100-based split, the CALX133ACE-based split antigens are stable for at least 6 months at 4 °C. Moreover, immunization of mice with CALX133ACE-based split NYMC X-179A (H1N1) antigens harboring 10 to 30-fold less antigen than the commercialized trivalent inactivated vaccines Vaxigrip® or Fluviral® induced comparable efficient protection and neutralizing antibody responses against A(H1N1)pdm09 infection. Taken together, our results demonstrate for the first time the use of a calixarene-based detergent as an efficient splitting agent for the production of optimized influenza split antigens, paving the way for significant improvement in the vaccine manufacturing process, notably with regard to the current regulation on the prohibition of endocrine disruptors, such as Triton X-100.

A Glycolipid Adjuvant, 7DW8-5, Enhances the Protective Immune Response to the Current Split Influenza Vaccine in Mice.

Vaccination is an effective strategy to control influenza disease. Adjuvants enhance the efficacy of vaccines, but few adjuvants are approved for human use, so novel, safe, and effective adjuvants are urgently needed. The glycolipid adjuvant 7DW8-5 has shown adjuvanticity to malaria vaccine; however, its adjuvant effect for seasonal influenza vaccine remains unknown. Here, we evaluated the adjuvanticity of 7DW8-5 to a quadrivalent split influenza vaccine in a mouse model. 7DW8-5 significantly enhanced virus-specific antibody production when administrated with influenza vaccine compared with that of vaccine alone; 10 μg of 7DW8-5 induced similar antibody levels to those induced by alum. Mouse body weight loss was reduced and, notably, the survival rate was increased in the vaccine plus 7DW8-5 group compared with that in the vaccine plus alum group. Our results indicate that the glycolipid 7DW8-5 is a promising adjuvant for influenza vaccine.