Psychosocial predictors of the innate immune response to influenza vaccination.

Experimental activation of the innate immune system has contributed significantly to both our understanding of how psychological factors influence immune function as well as how immune activity influences the brain and behavior. The annual influenza vaccine can be used to interrogate the effects of mild immune stimulation on day-to-day changes in psychological processes in human subjects that range across the lifespan and in both clinical and non-clinical populations. Yet, the immune response to the influenza vaccine in the days immediately following its administration are not well characterized. The present study describes changes in inflammatory and antiviral gene expression within circulating immune cells, plasma cytokines, and C-reactive protein (CRP) following receipt of the flu vaccine, and further reports the association between several common behavioral health factors and the acute immune response. Participants were 65 adults (mean age 18.81 ± 1.03 years; 66.2% female) who provided a blood sample immediately before and then 24 h after receiving the vaccine. A subsample also provided additional blood samples at 48 and 72 h. Plasma was assayed for CRP, IL-6, IL-10, IL-8, TNF-α, and IFN-γ, and peripheral blood mononuclear cell RNA was sequenced for evidence of change in expression of an a priori set of type 1 interferon (IFN) and inflammatory response genes (INFLAM). Plasma cytokines, CRP, and IFN response genes increased 24 h after vaccination, all ps < .001. The increase in IFN gene expression correlated with the observed increase in plasma cytokines and CRP, p < .0001. The immune response to influenza vaccination at 24-hours was moderated by anxiety symptoms, BMI, being female, sleep, and history of influenza vaccination. These factors and their associations with common immune challenges may be useful in studies interrogating the origins of immune dysregulation. The annual influenza vaccine is an accessible and reliable exogenous activator of both circulating and transcriptional markers of innate immune reactivity, with sensitivity to behavioral health factors relevant for psychoneuroimmunology research.

In situ bio-mineralized Mn nanoadjuvant enhances anti-influenza immunity of recombinant virus-like particle vaccines.

Virus like particles (VLPs) have been well recognized as one of the most important vaccine platforms due to their structural similarity to natural viruses to induce effective humoral and cellular immune responses. Nevertheless, lack of viral nucleic acids in VLPs usually leads the vaccine candidates less efficient in provoking innate immune against viral infection. Here, we constructed a biomimetic dual antigen hybrid influenza nanovaccines THM-HA@Mn with robust immunogenicity via in situ synthesizing a stimulator of interferon genes (STING) agonist Mn3O4 inside the cavity of a recombinant Hepatitis B core antigen VLP (HBc VLP) having fused SpyTag and influenza M2e antigen peptides (Tag-HBc-M2e, THM for short), followed by conjugating a recombinant hemagglutinin (rHA) antigen on the surface of the nanoparticles through SpyTag/SpyCatcher ligating. Such inside Mn3O4 immunostimulator-outside rHA antigen design, together with the chimeric M2e antigen on the HBc skeleton, enabled the synthesized hybrid nanovaccines THM-HA@Mn to well imitate the spatial distribution of M2e/HA antigens and immunostimulant in natural influenza virus. In vitro cellular experiments indicated that compared with the THM-HA antigen without Mn3O4 and a mixture vaccine consisting of THM-HA + MnOx, the THM-HA@Mn hybrid nanovaccines showed the highest efficacies in dendritic cells uptake and in promoting BMDC maturation, as well as inducing expression of TNF-α and type I interferon IFN-ß. The THM-HA@Mn also displayed the most sustained antigen release at the injection site, the highest efficacies in promoting the DC maturation in lymph nodes and germinal center B cells activation in the spleen of the immunized mice. The co-delivery of immunostimulant and antigens enabled the THM-HA@Mn nanovaccines to induce the highest systemic antigen-specific antibody responses and cellular immunogenicity in mice. Together with the excellent colloid dispersion stability, low cytotoxicity, as well as good biosafety, the synthetic hybrid nanovaccines presented in this study offers a promising strategy to design VLP-based vaccine with robust natural and adaptive immunogenicity against emerging viral pathogens.

Structural analysis of a soluble polysaccharide GSPA-0.3 from the root of Panax ginseng C. A. Meyer and its adjuvant activity with mechanism investigation.

A novel polysaccharide (GSPA-0.3) was isolated and purified from the root of cultivated Panax ginseng C. A. Meyer, and its structure, adjuvant activities, and mechanisms for inducing the maturation of mouse dendritic 2.4 cells (DC2.4) were extensively studied. Fraction GSPA-0.3, mainly composed by the galacturonic acid, galactose, arabinose, glucose, rhamnose, mannose, and xylose, had a molecular weight of 62,722 Da. The main chain of GSPA-0.3 was composed of →3)-α-L-Rhap-(1→, →4)-α-D-GalpA-(1→, and →3, 4)-α-D-GalpA-(1→. Branched chains comprised α-L-Araf-(1→3, 5)-α-L-Araf-(1→5)-α-L-Araf-(1→, α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glcp-(1→, ß-D-Galp-(1→4)-ß-D-Galp-(1→4)-ß-D-Galp-(1→, and α-D-GalpA-(1→ units connected to the C3 position of →3, 4)-α-D-GalpA-(1→. In vivo, GSPA-0.3 was found to stimulate the production of IgG, IgG1, and IgG2a; increase the splenocyte proliferation index; and promote the expression of GATA-3, T-bet, IFN-γ, and IL-4 in H1N1 vaccine-immunized mice. Moreover, GSPA-0.3 significantly increased the levels of neutralizing antibodies in the mice, and its adjuvant activity was found to be superior to aluminum adjuvant (Alum adjuvant). Mechanistic investigations showed that GSPA-0.3 activated the TLR4-dependent pathway by upregulating the expressions of TLR4, MyD88, TRAF-6, and NF-κB proteins and gens. The results presented herein suggested that GSPA-0.3 could significantly promote the efficacy of the H1N1 vaccine by modulating Th1/Th2 response via the TLR4-MyD88-NF-κB signaling pathway.

[Application and prospect of natural active ingredients of traditional Chinese medicine in immunological adjuvant for influenza vaccine].

Vaccination is an effective method for preventing influenza, and adjuvants can enhance the immune response intensity and persistence of influenza vaccines. However, there are currently shortcomings in clinical adjuvant approvals, ineffectiveness against weak antigens, and a tendency to cause headaches. Therefore, the development of safe and effective novel adjuvants for influenza vaccines is particularly important to enhance vaccine immunogenicity and safety. Given the wide range of sources, high safety, and biodegradability of traditional Chinese medicine(TCM), some studies have described it as a vaccine adjuvant. This article reviewed the current status and challenges of influenza vaccine adjuvants, summarized the types of TCM adjuvants, the safety and immunomodulatory effects of natural active ingredients from TCM combined with influenza vaccines, the role of TCM adjuvants in antigen storage, antigen presentation capability, immune cells and cytokines, and immune responses, and analyzed the advantages and disadvantages of TCM adjuvants compared with small molecule adjuvants, with the aim of promoting the clinical development and commercialization of TCM adjuvants for influenza vaccines.

Influenza Vaccination Uptake and Associated Factors Among Adults With and Without Human Immunodeficiency Virus in a Large, Integrated Healthcare System.

BACKGROUND: Influenza vaccination is recommended for adults regardless of human immunodeficiency virus (HIV) status. There may be facilitators or barriers to vaccinating people with HIV (PWH) that differ from people without HIV (PWoH). We sought to describe the uptake of influenza vaccination by HIV status and identify factors associated with vaccination. METHODS: We abstracted data from the electronic health records of PWH and PWoH in Kaiser Permanente Northern California during 6 influenza seasons (2013-2018). We determined vaccination uptake and used Poisson regression models to evaluate factors associated with vaccination in PWH and PWoH. RESULTS: 9272 PWH and 194 393 PWoH matched by age, sex, and race/ethnicity were included (mean age: 48 vs 49 years; men: 91% vs 90%; White race: 53% for both groups). PWH were more likely to receive the influenza vaccine (65-69% across years for PWH and 37-41% for PWoH) with an adjusted risk ratio for all years of 1.48 (95% CI: 1.46-1.50). For PWH, lower vaccination uptake was associated with several factors that suggested more complex health needs, such as lower CD4 cell counts, higher HIV viral loads, prior depression diagnoses, having Medicare insurance, and having a higher number of comorbidities. Associations with vaccination uptake were attenuated in PWH, compared with PWoH, for smoking, alcohol, and demographic factors. CONCLUSIONS: PWH had an almost 50% higher uptake of influenza vaccination than PWoH, possibly reflecting greater engagement with the healthcare system. We also found that PWH with more complex health needs had reduced vaccination uptake. Findings may inform outreach strategies to increase influenza vaccination in PWH.

Improvement influenza vaccine immune responses with traditional Chinese medicine and its active ingredients.

The current influenza vaccines are unable to provide effective protection in many cases, like influenza viruses strain antigenic drift or shift, and the influenza continues to cause significant annual morbidity and mortality. Improving the immune response to influenza vaccination is an unmet need. Traditional Chinese medicine (TCM) and its active ingredients are commonly known to have immunomodulatory properties. We therefore compared influenza vaccination alone or formulated with Astragali Radix (Huangqi in Chinese), and several representative ingredients of TCM, including lentinan (polysaccharide), panax notoginseng saponins (saponin), breviscapine (flavone), andrographolide (terpenoid), and a Chinese herbal compound (kangai) for their potential to enhance immune responses to influenza vaccine in mice. We found that all these TCM-adjuvants were able to increase hemagglutination inhibition (HAI) antibody titers, splenocyte proliferation, splenic T cell differentiation, bone marrow dendritic cell maturity, and both Th1 and Th2 cytokine secretion of influenza vaccine to varying degrees, and that had the characteristics of no excessive inflammatory responses and bidirectional regulation simultaneously. Taken together, our findings show that Astragali Radix exerts a more comprehensive effect on vaccine immunity, on both innate and adaptive immunity. The effects of lentinan and andrographolide on adaptive immunity were more significant, while the effects of breviscapine on innate immunity were stronger, and the other two TCM adjuvants were weaker. As the first report of a comprehensive evaluation of TCM adjuvants in influenza vaccines, the results suggest that TCM and their active ingredients are good candidates for enhancing the immune response of influenza vaccines, and that suitable TCMs can be selected based on the adjuvant requirements of different vaccines.

Cultivated Artemisia rupestris L. polysaccharide CARP2 as an adjuvant for influenza vaccines to prolong immune responses.

In the study, the adjuvant features of the immunoregulatory polysaccharide component CARP2 isolated from cultivated Artemisia rupestris L. for influenza virus vaccine (IVV) and the mechanism responsible for its action in DCs were further explored. CARP2 showed a typical absorbance peak of polysaccharides in spectral analysis. At two doses of CARP2-adjuvanted IVV, IgG, hemagglutination inhibition (HI) titers, and effector/memory T cells were generated and lasted for 275 days without adverse events. CARP2 primed rapid HI and IgG, IgG2a/IgG1 ratio, splenocyte proliferation, and cytotoxic T lymphocyte (CTL), and facilitated the generation of INF-γ and IL-4 by activating DCs and regulatory T cells (Tregs). Additionally, CARP2 achieved the ten-fold dose-sparing effect. In vitro, CARP2 stimulated DCs to prime the production of Th1/Th2 cytokines and CCR7 and activated MyD88-dependent pathway by upregulating the expressions of TLR4, MyD88, TRAF-6, and p65. In contrast, MyD88, TRAF-6, and NF-κB inhibitors partially blocked the effect through reducing related cytokines and proteins. Overall, CARP2 promoted IVV efficacy, which was involved in the modulation of Th1/Th2 responses and shifted toward Th1-polarizing response via TLR4/MyD88/TRAF/NF-κB activation in DCs.

T Cell Transcriptional Signatures of Influenza A/H3N2 Antibody Response to High Dose Influenza and Adjuvanted Influenza Vaccine in Older Adults.

Older adults experience declining influenza vaccine-induced immunity and are at higher risk of influenza and its complications. For this reason, high dose (e.g., Fluzone) and adjuvanted (e.g., Fluad) vaccines are preferentially recommended for people age 65 years and older. However, T cell transcriptional activity shaping the humoral immune responses to Fluzone and Fluad vaccines in older adults is still poorly understood. We designed a study of 234 older adults (≥65 years old) who were randomly allocated to receive Fluzone or Fluad vaccine and provided blood samples at baseline and at Day 28 after immunization. We measured the humoral immune responses (hemagglutination inhibition/HAI antibody titer) to influenza A/H3N2 and performed mRNA-Seq transcriptional profiling in purified CD4+ T cells, in order to identify T cell signatures that might explain differences in humoral immune response by vaccine type. Given the large differences in formulation (higher antigen dose vs adjuvant), our hypothesis was that each vaccine elicited a distinct transcriptomic response after vaccination. Thus, the main focus of our study was to identify the differential gene expression influencing the antibody titer in the two vaccine groups. Our analyses identified three differentially expressed, functionally linked genes/proteins in CD4+ T cells: the calcium/calmodulin dependent serine/threonine kinase IV (CaMKIV); its regulator the TMEM38B/transmembrane protein 38B, involved in maintenance of intracellular Ca2+ release; and the transcriptional coactivator CBP/CREB binding protein, as regulators of transcriptional activity/function in CD4+ T cells that impact differences in immune response by vaccine type. Significantly enriched T cell-specific pathways/biological processes were also identified that point to the importance of genes/proteins involved in Th1/Th2 cell differentiation, IL-17 signaling, calcium signaling, Notch signaling, MAPK signaling, and regulation of TRP cation Ca2+ channels in humoral immunity after influenza vaccination. In summary, we identified the genes/proteins and pathways essential for cell activation and function in CD4+ T cells that are associated with differences in influenza vaccine-induced humoral immunity by vaccine type. These findings provide an additional mechanistic perspective for achieving protective immunity in older adults.

Enhanced Influenza Immunity by Nasal Mucosal Administration of the TPGS-Modified Liposomal Vaccine.

Influenza infection is difficult to prevent, control, and treat because of rapid viral mutation, fast disease progression, and high mortality. Vaccination is the main means by which to prevent and control influenza, but effectiveness is limited in that poor cellular uptake and weak immunogenicity of vaccines provides less than optimal host protection. Liposomal influenza vaccines are a promising strategy to overcome these limitations and the use of liposomal immune modulators and intranasal administration of liposomal influenza vaccines may be a means by which to improve influenza protection. The cationic lipids, i.e., dimethyldioctadecylammonium (DDA), 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine (DSPC), and D-α-tocopherol polyethylene glycol 1000 (TPGS) can form blank liposomes, which can incorporate influenza antigens to produce an influenza vaccine (DDA-DSPC-TPGS). Herein, this vaccine was shown to induce dendritic cell maturation, increase host cellular uptake of the vaccine, and enhance immune responses both in vitro and in vivo. The addition of TPGS, as an amphiphilic immune adjuvant, significantly reduced the toxicity of the DDA liposomal influenza vaccine. Further, the polyethylene glycol component and tocopherol structure of TPGS enhanced the cellular uptake of the vaccine by means of stealth properties and the capacity to inhibit cellular efflux. After nasal mucosal immunization, enhanced cellular uptake rates and abundant immune cells in the nasopharyngeal-associated lymphoid tissue promoted the production of immunoglobulin A, immunoglobulin G1, and interferon-γ, which in turn mediated a more robust immune response against influenza virus. In summary, the DDA-DSPC-TPGS influenza vaccine is a safe and effective means by which to activate the immune system. The results herein provide an effective strategy by which to overcome current difficulties associated with the prevention and treatment of influenza.

COVID-19 Vaccine Hesitancy in Israel Immediately Before the Vaccine Operation.

The development of a vaccine for COVID-19 presented hope for a way out of the global crisis caused by the virus. However, a potential barrier may be vaccine hesitancy, and identifying the factors that affect it is critical, especially concerning a new vaccine technology. The purpose of this research is to identify the factors that effects vaccine hesitancy by using a holistic view. The data were collected from 504 people in December 2020, 3 days before the vaccine operation started in Israel. The analysis included three categories of determinants: (1) contextual influences; (2) health records; and (3) perceived health attitudes. The results indicate that different sets of variables affect willingness to accept the vaccine among the whole spectrum of the vaccine-hesitant and the undecided subsample. In the full sample, gender, age, income, influenza vaccine, perceived trust, perceived susceptibility, perceived benefits, and perceived barriers affected vaccine acceptance. The perceived level of suffering from COVID-19 was associated with willingness to vaccinate, and when religious beliefs increased, the intention to vaccinate decreased. For the undecided subsample, the factors included gender, influenza vaccine, trust in the vaccine company, and perceived vaccine benefits and barriers. The results suggest that efforts of governments and health institutions should focus on women and highlight the vaccine as an opportunity to "go back to normal" without worries. Those results will help implement vaccine strategy in the following cases: if infant vaccination is pursued and if emergency vaccines or new vaccine technologies emerge for another pandemic as well.

Metal-Organic Coordination Polymer for Delivery of a Subunit Broadly Acting Influenza Vaccine.

A zinc-carnosine (ZnCar) metal-organic coordination polymer was fabricated in biologically relevant N-(2-hydroxyethyl)piperazine-N'-ethanesulfonic acid (HEPES) buffer for use as a vaccine platform. In vitro, ZnCar exhibited significantly less cytotoxicity than a well-established zeolitic imidazolate framework (ZIF-8). Adsorption of CpG on the ZnCar surface resulted in enhanced innate immune activation compared to soluble CpG. The model antigen ovalbumin (OVA) was encapsulated in ZnCar and exhibited acid-sensitive release in vitro. When injected intramuscularly on days 0 and 21 in C57BL/6 mice, OVA-specific serum total IgG and IgG1 were significantly greater in all groups with ZnCar and antigen compared to soluble controls. Th1-skewed IgG2c antibodies were significantly greater in OVA and CpG groups delivered with ZnCar for all time points, regardless of whether the antigen and adjuvant were co-formulated in one material or co-delivered in separate materials. When broadly acting Computationally Optimized Broadly Reactive Antigen (COBRA) P1 influenza hemagglutinin (HA) was ligated to ZnCar via its His-tag, significantly greater antibody levels were observed at all time points compared to soluble antigen and CpG. ZnCar-formulated antigen elicited increased peptide presentation to B3Z T cells in vitro and production of IL-2 after ex vivo antigen recall of splenocytes isolated from vaccinated mice. Overall, this work displays the formation of a zinc-carnosine metal-organic coordination polymer that can be applied as a platform for recombinant protein-based vaccines.

Improving adjuvanticity of crude polysaccharides from cultivated Artemisia rupestris L. for influenza vaccine by promoting long-term immunity and TH1/TH2 response with dose-sparing effect.

ETHNOPHARMACOLOGICAL RELEVANCE: Influenza virus vaccines (IVV) with balanced TH1/TH2 responses are critical for controlling seasonal influenza. Emerging evidences suggest that herbal polysaccharides can induce potent TH1 or mixed TH1/TH2 responses. AIM OF STUDY: The study aims to determine the efficacy and safety of crude polysaccharides from cultivated Artemisia rupestris L. (CPCAR) as an adjuvant for IVV. MATERIALS AND METHODS: CPCAR was prepared with hot extraction and ethanol precipitation method and primary physico-chemical characters were tested. Mice were vaccinated by subcutaneous route with IVV formulated with different dose of CPCAR to detecting the elicited TH1/TH2 responses and long-term immune responses with dose-sparing sparing effect. RESULTS: IVV formulated with CPCAR without LPS contamination could augment balanced TH1/TH2 responses, as indicated by early IgG response, hemagglutination inhibition (HAI) antibodies, effector T-cells, and cytotoxic T lymphocytes (CTL). Moreover, CPCAR elicited long-term IgG, HAI antibodies, memory T cells, and balanced CD4/CD8 responses within 168 days after vaccination. Compared with IVV alone, a low or high dose of IVV formulated with CPCAR improved the levels of IgG, IgG1, and IgG2a and enhanced memory T cells and balanced CD4/CD8 responses, displaying a 10-fold dose-sparing effect. As determined by IgE response and monitoring results of weekly body weight and daily symptoms after vaccination, anaphylaxis or adverse effect was not observed. CONCLUSIONS: Collectively, the study demonstrated the potential of CPCAR as an aqueous polysaccharide adjuvant for IVV to induce rapid and balanced TH1/TH2 responses and long-lasting immunity with dose-sparing effect.

Dried Ginger Extract Restores the T Helper Type 1/T Helper Type 2 Balance and Antibody Production in Cyclophosphamide-Induced Immunocompromised Mice after Flu Vaccination.

Dried ginger (Zingiberis Processum Rhizoma (ZR)) is frequently used to prevent or treat common cold and flu. This study aimed to investigate the influence of ZR extracts on influenza-specific antibody production in cyclophosphamide (Cy)-induced immunocompromised mice. Female BALB/c mice were injected three times with saline or Cy. To investigate the effect of ZR, either distilled water or ZR was administered orally to mice daily for 10 days after Cy injection. After ZR administration, the mice were immunized with the 2017/2018 influenza vaccine. Pretreatment with ZR extracts enhanced influenza-specific antibody production in Cy-induced immunocompromised mice after flu vaccination and restored the influenza antigen-specific T helper (Th) type 1/Th2 balance to the normal state. Further, ZR suppressed the eosinophil enrichment caused by Cy injection in the spleen. We demonstrated that ZR can be used to increase antibody production in immunocompromised individuals before vaccination.

Immunomodulatory Effects of α-Tocopherol on the H1N1 Influenza Vaccine: Improving the Potency and Efficacy of the Influenza Vaccine in Aged Mice.

Declined immune response is the main cause of decreased potency of the influenza vaccine in the elderly, regardless of virus mutations. Herein, we hypothesized that the addition of α-tocopherol to the influenza vaccine formulation might increase vaccine potency and efficacy. Hemagglutinin of the H1N1 virus was formulated in Alum and α-tocopherol, and then aged (16-20-month-old) and young (6-8-week-old) mice were immunized subcutaneously two times with 2-week intervals with 5 µg of different vaccine formulations. Two weeks after the final boosting, IFN-γ and IL-4 cytokines were assessed by using ELISA. Humoral immune responses were assessed by hemagglutination inhibition (HI). In addition, vaccine efficacy was determined by intranasal viral challenge of mice using mouse-adapted H1N1 virus. Our results showed that the new vaccine formulation improved IFN-γ and IL-4 responses in the experimental mice. However, the increase was evident mainly in the aged group and, to some extent, in the young group. Results from the HI assay showed that α-tocopherol in the vaccine formulation could increase HI activity in both young and aged mice. Furthermore, α-tocopherol, as an adjuvant, increased the protectivity of the influenza vaccine in both aged and young groups through the decreased lung viral load and increased survival rate of the experimental mice. In conclusion, it seems that α-tocopherol can not only be used as an appropriate adjuvant for aged people, but also empower old and worn out cells to increase the effectiveness of the vaccine in the elderly.

Effect and Tolerability of a Nutritional Supplement Based on a Synergistic Combination of ß-Glucans and Selenium- and Zinc-Enriched Saccharomyces cerevisiae (ABB C1®) in Volunteers Receiving the Influenza or the COVID-19 Vaccine: A Randomized, Double-Blind, Placebo-Controlled Study.

A single-center, randomized, double-blind, placebo-controlled study was conducted in 72 volunteers who received a synergistic combination of yeast-based ingredients with a unique ß-1,3/1,6-glucan complex and a consortium of heat-treated probiotic Saccharomyces cerevisiae rich in selenium and zinc (ABB C1®) or placebo on the next day after getting vaccinated against influenza (Chiromas®) (n = 34) or the COVID-19 (Comirnaty®) (n = 38). The duration of treatment was 30 and 35 days for the influenza and COVID-19 vaccine groups, respectively. Mean levels of CD4+T cells increased from 910.7 at baseline to 1000.2 cells/µL after the second dose of the COVID-19 vaccine in the ABB C1® group, whereas there was a decrease from 1055.1 to 929.8 cells/µL in the placebo group. Changes of CD3+T and CD8+T lymphocytes showed a similar trend. In the COVID-19 cohort, the increases in both IgG and IgM were higher in the ABB C1® supplement than in the placebo group. Serum levels of selenium and zinc showed a higher increase in subjects treated with the active product than in those receiving placebo. No serious adverse events related to ABB C1® or tolerance issues were reported. The study findings validate the capacity of the ABB C1® product to stimulate trained immunity.

Effect of processed aloe vera gel on immunogenicity in inactivated quadrivalent influenza vaccine and upper respiratory tract infection in healthy adults: A randomized double-blind placebo-controlled trial.

BACKGROUND: Aloe vera is a functional food with various pharmacological functions, including an immune-modulating effect. Until now, A. vera has never been studied as an adjuvant in influenza vaccine, and its effects on upper respiratory tract infection (URI) are unknown. PURPOSE: The objective of our study was to investigate the effect of processed A. vera gel (PAG) on immunogenicity of quadrivalent inactivated influenza vaccine and URI in healthy adults. STUDY DESIGN: A randomized, double-blind, placebo-controlled clinical trial was performed. METHODS: This study was conducted in 100 healthy adults at a single center from September 2017 to May 2018. Subjects were randomly divided into a PAG group (n = 50) and a placebo group (n = 50). The enrolled subjects were instructed to ingest the study drug for 8 weeks. The participants received a single dose of quadrivalent inactivated influenza vaccine after taking the study drug for the first 4 weeks of the study. The primary endpoint was seroprotection rate against at least one viral strain at 4 weeks post-vaccination. Other outcomes were seroprotection rate at 24 weeks post-vaccination, seroconversion rate, geometric mean fold increase (GMFI) at 4 and 24 weeks post-vaccination, seroprotection rate ratio and geometric mean titer ratio (GMTR) at 4 weeks post-vaccination between PAG and placebo groups, and incidence, severity, and duration of URI. RESULTS: The European Committee for proprietary medicinal products (CPMP) evaluation criteria were met at least one in the PAG and placebo groups for all strains. However, there was no significant difference in the seroprotection rate at 4 weeks post-vaccination against all strains in both PAG and placebo groups. Among secondary endpoints, the GMFI at 4 weeks post-vaccination for the A/H3N2 was significantly higher in the PAG than in placebo group. The GMTR as adjuvant effect was 1.382 (95% CI, 1.014-1.1883). Kaplan-Meier curve analysis showed a reduction in incidence of URI (p = 0.035), and a generalized estimating equation model identified a decrease in repeated URI events (odds ratio 0.57; 95% CI, 0.39-0.83; p = 0.003) in the PAG group. CONCLUSIONS: Oral intake of PAG did not show a significant increase in seroprotection rate from an immunogenicity perspective. However, it reduced the number of URI episodes. A well-designed further study is needed on the effect of PAG's antibody response against A/H3N2 in the future.

Quick and improved immune responses to inactivated H9N2 avian influenza vaccine by purified active fraction of Albizia julibrissin saponins.

BACKGROUND: H9N2 Low pathogenic avian influenza virus (LPAIV) raises public health concerns and its eradication in poultry becomes even more important in preventing influenza. AJSAF is a purified active saponin fraction from the stem bark of Albizzia julibrissin. In this study, AJSAF was evaluated for the adjuvant potentials on immune responses to inactivated H9N2 avian influenza virus vaccine (IH9V) in mice and chicken in comparison with commercially oil-adjuvant. RESULTS: AJSAF significantly induced faster and higher H9 subtype avian influenza virus antigen (H9-Ag)-specific IgG, IgG1, IgG2a and IgG2b antibody titers in mice and haemagglutination inhibition (HI) and IgY antibody levels in chicken immunized with IH9V. AJSAF also markedly promoted Con A-, LPS- and H9-Ag-stimulated splenocyte proliferation and natural killer cell activity. Furthermore, AJSAF significantly induced the production of both Th1 (IL-2 and IFN-γ) and Th2 (IL-10) cytokines, and up-regulated the mRNA expression levels of Th1 and Th2 cytokines and transcription factors in splenocytes from the IH9V-immunized mice. Although oil-formulated inactivated H9N2 avian influenza vaccine (CH9V) also elicited higher H9-Ag-specific IgG and IgG1 in mice and HI antibody titer in chicken, this robust humoral response was later produced. Moreover, serum IgG2a and IgG2b antibody titers in CH9V-immunized mice were significantly lower than those of IH9V alone group. CONCLUSIONS: AJSAF could improve antigen-specific humoral and cellular immune responses, and simultaneously trigger a Th1/Th2 response to IH9V. AJSAF might be a safe and efficacious adjuvant candidate for H9N2 avian influenza vaccine.

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

BACKGROUND AND PURPOSE: Adjuvant 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. METHODS: Isopropyl 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. RESULTS: Particle 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. CONCLUSION: Emulsions 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.

Influenza vaccination in early Alzheimer's disease rescues amyloidosis and ameliorates cognitive deficits in APP/PS1 mice by inhibiting regulatory T cells.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder strongly correlated with a dysfunctional immune system. Our previous results demonstrated that inactivated influenza vaccine (IIV) facilitates hippocampal neurogenesis and blocks lipopolysaccharide (LPS)-induced cognitive impairment. However, whether IIV improves cognitive deficits in an AD mouse model remains unclear. In addition, early interventions in AD have been encouraged in recent years. Here, we investigated whether IIV immunization at the preclinical stage of AD alters the brain pathology and cognitive deficits in an APP/ PS1 mouse model. METHODS: We assessed spatial learning and memory using Morris water maze (MWM). The brain ß-amyloid (Aß) plaque burden and activated microglia were investigated by immunohistochemistry. Furthermore, flow cytometry was utilized to analyze the proportions of Treg cells in the spleen. A cytokine antibody array was performed to measure the alteration of cytokines in the brain and peripheral immune system. RESULTS: Five IIV immunizations activated microglia, reduced the Aß burden and improved the cognitive impairment. Simultaneously, the IIV-induced immune response broke peripheral immunosuppression by reducing Foxp3+ regulatory T cell (Treg) activities, whereas the restoration of Treg level in the periphery using all-trans retinoic acid (ATRA) blunted the protective effects of IIV on Aß burden and cognitive functions. Interestingly, IIV immunization might increase proinflammatory and anti-inflammatory cytokine expression in the brain of APP/PS1 mice, enhanced microglial activation, and enhanced the clustering and phagocytosis of Aß, thereby creating new homeostasis in the disordered immune microenvironment. CONCLUSIONS: Altogether, our results suggest that early multiple IIV immunizations exert a beneficial immunomodulatory effect in APP/PS1 mice by breaking Treg-mediated systemic immune tolerance, maintaining the activation of microglia and removing of Aß plaques, eventually improving cognitive deficits.

Formulation Design, Optimization and In Vivo Evaluations of an α-Tocopherol-Containing Self-Emulsified Adjuvant System using Inactivated Influenza Vaccine.

α-Tocopherol has been used as an immune supplement in humans, as an emulsion adjuvant component in several veterinary vaccines as well as an immunomodulatory component of AS03, an emulsion adjuvant that was used in an H1N1 pandemic vaccine (Pandemrix). AS03 is manufactured using microfluidization and high-pressure homogenization. Such high energy and complex manufacturing processes make it difficult and expensive to produce emulsion adjuvants on a large scale, especially in developing countries. In this study we have explored simpler, comparatively inexpensive methods, to formulate emulsion adjuvants containing α-tocopherol, that have the potential to be made in any well-established scale-up facility. This might facilitate producing and stock-piling adjuvant doses and therefore aide in pandemic preparedness. We used design of experiment as a tool to explore incorporating α-tocopherol into self-emulsified systems containing squalene oil and polysorbate 80. We created novel self-emulsified adjuvant systems (SE-AS) and evaluated their potency in vivo in BALB/c mice with inactivated quadrivalent influenza vaccine (QIV) and tested the cellular and humoral immune responses against the four vaccine strains.