An innate immune signature induced by AS01- or AS03-adjuvanted vaccines predicts the antibody response magnitude and quality consistently over time.

Background: Antibody-mediated protection can depend on mechanisms varying from neutralization to Fc-dependent innate immune-cell recruitment. Adjuvanted vaccine development relies on a holistic understanding of how adjuvants modulate the quantity/titer and quality of the antibody response. Methods: A Phase 2 trial (ClinicalTrials.gov: NCT00805389) evaluated hepatitis B vaccines formulated with licensed adjuvants (AS01B, AS01E, AS03, AS04 or Alum) in antigen-naïve adults. The trial investigated the role of adjuvants in shaping antibody-effector functions, and identified an innate transcriptional response shared by AS01B, AS01E and AS03. We integrated previously reported data on the innate response (gene expression, cytokine/C-reactive protein levels) and on quantitative/qualitative features of the mature antibody response (Fc-related parameters, immunoglobulin titers, avidity). Associations between the innate and humoral parameters were explored using systems vaccinology and a machine-learning framework. Results: A dichotomy in responses between AS01/AS03 and AS04/Alum (with the former two contributing most to the association with the humoral response) was observed across all timepoints of this longitudinal study. The consistent patterns over time suggested a similarity in the impacts of the two-dose immunization regimen, year-long interval, and non-adjuvanted antigenic challenge given one year later. An innate signature characterized by interferon pathway-related gene expression and secreted interferon-γ-induced protein 10 and C-reactive protein, which was shared by AS01 and AS03, consistently predicted both the qualitative antibody response features and the titers. The signature also predicted from the antibody response quality, the group of adjuvants from which the administered vaccine was derived. Conclusion: An innate signature induced by AS01- or AS03-adjuvanted vaccines predicts the antibody response magnitude and quality consistently over time.

Relative vaccine effectiveness of MF59-adjuvanted vs high-dose trivalent inactivated influenza vaccines for prevention of test-confirmed influenza hospitalizations during the 2017-2020 influenza seasons.

OBJECTIVES: This study evaluated relative vaccine effectiveness (rVE) of MF59-adjuvanted trivalent inactivated influenza vaccine (aTIV) vs high-dose trivalent inactivated influenza vaccine (HD-TIV) for prevention of test-confirmed influenza emergency department visits and/or inpatient admissions ("ED/IP") and for IP admissions alone pooled across the 2017-2020 influenza seasons. Exploratory individual season analyses were also performed. METHODS: This retrospective test-negative design study included United States (US) adults age ≥65 years vaccinated with aTIV or HD-TIV who presented to an ED or IP setting with acute respiratory or febrile illness during the 2017-2020 influenza seasons. Test-positive cases and test-negative controls were grouped by vaccine received. The rVE of aTIV vs HD-TIV was evaluated using a combination of inverse probability of treatment weighting and logistic regression to adjust for potential confounders. RESULTS: Pooled analyses over the three seasons found no significant differences in the rVE of aTIV vs HD-TIV for prevention of test-confirmed influenza ED/IP (-2.5% [-19.6, 12.2]) visits and admissions or IP admissions alone (-1.6% [-22.5, 15.7]). The exploratory individual season analyses also showed no significant differences. CONCLUSIONS: Evidence from the 2017-2020 influenza seasons indicates aTIV and HD-TIV are comparable for prevention of test-confirmed influenza ED/IP visits in US adults age ≥65 years.

Safety and Immunogenicity of a DNA Vaccine With Subtype C gp120 Protein Adjuvanted With MF59 or AS01B: A Phase 1/2a HIV-1 Vaccine Trial.

BACKGROUND: An effective vaccine is required to end the HIV pandemic. We evaluated the safety and immunogenicity of a DNA (DNA-HIV-PT123) vaccine with low- or high-dose bivalent (TV1.C and 1086.C glycoprotein 120) subtype C envelope protein combinations, adjuvanted with MF59 or AS01B. METHODS: HIV Vaccine Trials Network (HVTN)108 was a randomized, placebo-controlled, double-blind, phase 1/2a trial conducted in the United States and South Africa. HIV-negative adults were randomly assigned to 1 of 7 intervention arms or placebo to assess DNA prime with DNA/protein/adjuvant boosts, DNA/protein/adjuvant co-administration, and low-dose protein/adjuvant regimens. HVTN111 trial participants who received an identical regimen were also included. Outcomes included safety and immunogenicity 2 weeks and 6 months after final vaccination. RESULTS: From June 2016 to July 2018, 400 participants were enrolled (N = 334 HVTN108, N = 66 HVTN111); 370 received vaccine and 30 received placebo. There were 48 grade 3 and 3 grade 4 reactogenicity events among 39/400 (9.8%) participants, and 32 mild/moderate-related adverse events in 23/400 (5.8%) participants. All intervention groups demonstrated high IgG response rates (>89%) and high magnitudes to HIV-1 Env gp120 and gp140 proteins; response rates for AS01B-adjuvanted groups approached 100%. V1V2 IgG magnitude, Fc-mediated functions, IgG3 Env response rates, and CD4+ T-cell response magnitudes and rates were higher in the AS01B-adjuvanted groups. The AS01B-adjuvanted low-dose protein elicited greater IgG responses than the higher protein dose. CONCLUSIONS: The vaccine regimens were generally well tolerated. Co-administration of DNA with AS01B-adjuvanted bivalent Env gp120 elicited the strongest humoral responses; AS01B-adjuvanted regimens elicited stronger CD4+ T-cell responses, justifying further evaluation.ClinicalTrials.gov registration: NCT02915016, registered 26 September 2016.

Relative Effectiveness of the MF59®-Adjuvanted Influenza Vaccine Versus High-Dose and Non-Adjuvanted Influenza Vaccines in Preventing Cardiorespiratory Hospitalizations During the 2019-2020 US Influenza Season.

BACKGROUND: Adults ≥ 65 years of age have suboptimal influenza vaccination responses compared to younger adults due to age-related immunosenescence. Two vaccines were specifically developed to enhance protection: MF59-adjuvanted trivalent influenza vaccine (aIIV3) and high-dose egg-based trivalent influenza vaccine (HD-IIV3e). METHODS: In a retrospective cohort study conducted using US electronic medical records linked to claims data during the 2019-2020 influenza season, we compared the relative vaccine effectiveness (rVE) of aIIV3 with HD-IIV3e and a standard-dose non-adjuvanted egg-based quadrivalent inactivated influenza vaccine (IIV4e) for the prevention of cardiorespiratory hospitalizations, including influenza hospitalizations. We evaluated outcomes in the "any" diagnosis position and the "admitting" position on the claim. A doubly robust methodology using inverse probability of treatment weighting and logistic regression was used to adjust for covariate imbalance. rVE was calculated as 100 * (1 - ORadjusted). RESULTS: The study included 4,299,594 adults ≥ 65 years of age who received aIIV3, HD-IIV3e, or IIV4e. Overall, aIIV3 was associated with lower proportions of cardiorespiratory hospitalizations with diagnoses in any position compared to HD-IIV3e (rVE = 3.9% [95% CI, 2.7-5.0]) or IIV4e (9.0% [95% CI, 7.7-10.4]). Specifically, aIIV3 was more effective compared with HD-IIV3e and IIV4e in preventing influenza hospitalizations (HD-IIV3e: 9.7% [95% CI, 1.9-17.0]; IIV4e: 25.3% [95% CI, 17.7-32.2]). Consistent trends were observed for admitting diagnoses. CONCLUSION: Relative to both HD-IIV3e and IIV4e, aIIV3 provided improved protection from cardiorespiratory or influenza hospitalizations.

A Phase 2 Clinical Trial to Evaluate the Safety, Reactogenicity, and Immunogenicity of Different Prime-Boost Vaccination Schedules of 2013 and 2017 A(H7N9) Inactivated Influenza Virus Vaccines Administered With and Without AS03 Adjuvant in Healthy US Adults.

INTRODUCTION: A surge of human influenza A(H7N9) cases began in 2016 in China from an antigenically distinct lineage. Data are needed about the safety and immunogenicity of 2013 and 2017 A(H7N9) inactivated influenza vaccines (IIVs) and the effects of AS03 adjuvant, prime-boost interval, and priming effects of 2013 and 2017 A(H7N9) IIVs. METHODS: Healthy adults (n = 180), ages 19-50 years, were enrolled into this partially blinded, randomized, multicenter phase 2 clinical trial. Participants were randomly assigned to 1 of 6 vaccination groups evaluating homologous versus heterologous prime-boost strategies with 2 different boost intervals (21 vs 120 days) and 2 dosages (3.75 or 15 µg of hemagglutinin) administered with or without AS03 adjuvant. Reactogenicity, safety, and immunogenicity measured by hemagglutination inhibition and neutralizing antibody titers were assessed. RESULTS: Two doses of A(H7N9) IIV were well tolerated, and no safety issues were identified. Although most participants had injection site and systemic reactogenicity, these symptoms were mostly mild to moderate in severity; injection site reactogenicity was greater in vaccination groups receiving adjuvant. Immune responses were greater after an adjuvanted second dose, and with a longer interval between prime and boost. The highest hemagglutination inhibition geometric mean titer (95% confidence interval) observed against the 2017 A(H7N9) strain was 133.4 (83.6-212.6) among participants who received homologous, adjuvanted 3.75 µg + AS03/2017 doses with delayed boost interval. CONCLUSIONS: Administering AS03 adjuvant with the second H7N9 IIV dose and extending the boost interval to 4 months resulted in higher peak antibody responses. These observations can broadly inform strategic approaches for pandemic preparedness. Clinical Trials Registration. NCT03589807.

Human Cytomegalovirus mRNA-1647 Vaccine Candidate Elicits Potent and Broad Neutralization and Higher Antibody-Dependent Cellular Cytotoxicity Responses Than the gB/MF59 Vaccine.

BACKGROUND: MF59-adjuvanted gB subunit (gB/MF59) vaccine demonstrated approximately 50% efficacy against human cytomegalovirus (HCMV) acquisition in multiple clinical trials, suggesting that efforts to improve this vaccine design might yield a vaccine suitable for licensure. METHODS: A messenger RNA (mRNA)-based vaccine candidate encoding HCMV gB and pentameric complex (PC), mRNA-1647, is currently in late-stage efficacy trials. However, its immunogenicity has not been compared to the partially effective gB/MF59 vaccine. We assessed neutralizing and Fc-mediated immunoglobulin G (IgG) effector antibody responses induced by mRNA-1647 in both HCMV-seropositive and -seronegative vaccinees from a first-in-human clinical trial through 1 year following third vaccination using a systems serology approach. Furthermore, we compared peak anti-gB antibody responses in seronegative mRNA-1647 vaccinees to that of seronegative gB/MF59 vaccine recipients. RESULTS: mRNA-1647 vaccination elicited and boosted HCMV-specific IgG responses in seronegative and seropositive vaccinees, respectively, including neutralizing and Fc-mediated effector antibody responses. gB-specific IgG responses were lower than PC-specific IgG responses. gB-specific IgG and antibody-dependent cellular phagocytosis responses were lower than those elicited by gB/MF59. However, mRNA-1647 elicited higher neutralization and antibody-dependent cellular cytotoxicity (ADCC) responses. CONCLUSIONS: Overall, mRNA-1647 vaccination induced polyfunctional and durable HCMV-specific antibody responses, with lower gB-specific IgG responses but higher neutralization and ADCC responses compared to the gB/MF59 vaccine. CLINICAL TRIALS REGISTRATION: NCT03382405 (mRNA-1647) and NCT00133497 (gB/MF59).

Safety, immunogenicity, and protection provided by unadjuvanted and adjuvanted formulations of a recombinant plant-derived virus-like particle vaccine candidate for COVID-19 in nonhuman primates.

Although antivirals are important tools to control severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, effective vaccines are essential to control the current coronavirus disease 2019 (COVID-19) pandemic. Plant-derived virus-like particle (VLP) vaccine candidates have previously demonstrated immunogenicity and efficacy against influenza. Here, we report the immunogenicity and protection induced in rhesus macaques by intramuscular injections of a VLP bearing a SARS-CoV-2 spike protein (CoVLP) vaccine candidate formulated with or without Adjuvant System 03 (AS03) or cytidine-phospho-guanosine (CpG) 1018. Although a single dose of the unadjuvanted CoVLP vaccine candidate stimulated humoral and cell-mediated immune responses, booster immunization (at 28 days after priming) and adjuvant administration significantly improved both responses, with higher immunogenicity and protection provided by the AS03-adjuvanted CoVLP. Fifteen micrograms of CoVLP adjuvanted with AS03 induced a polyfunctional interleukin-2 (IL-2)-driven response and IL-4 expression in CD4 T cells. Animals were challenged by multiple routes (i.e., intratracheal, intranasal, and ocular) with a total viral dose of 106 plaque-forming units of SARS-CoV-2. Lower viral replication in nasal swabs and bronchoalveolar lavage fluid (BALF) as well as fewer SARS-CoV-2-infected cells and immune cell infiltrates in the lungs concomitant with reduced levels of proinflammatory cytokines and chemotactic factors in the BALF were observed in animals immunized with the CoVLP adjuvanted with AS03. No clinical, pathologic, or virologic evidence of vaccine-associated enhanced disease was observed in vaccinated animals. The CoVLP adjuvanted with AS03 was therefore selected for vaccine development and clinical trials.

Lack of effects on female fertility or pre- and postnatal development of offspring in rats after exposure to AS03-adjuvanted recombinant plant-derived virus-like particle vaccine candidate for COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection resulting in the coronavirus disease 2019 (COVID-19) has afflicted tens of millions of people in a worldwide pandemic. A recently developed recombinant Plant-Derived Virus-Like Particle Vaccine candidate for COVID-19 (CoVLP) formulated with AS03 has been shown to be well-tolerated and highly immunogenic in healthy adults. Since the target population for the vaccine includes women of childbearing potential, the objective of the study was to evaluate any untoward prenatal and postnatal effects of AS03-adjuvanted CoVLP administered intramuscularly to Sprague-Dawley female rats before cohabitation for mating (22 and 8 days prior) and during gestation (Gestation Days [GD] 6 and 19). The embryo-fetal development (EFD) cohort was subjected to cesarean on GD 21 and the pre/post-natal (PPN) cohort was allowed to naturally deliver. Effects of AS03-adjuvanted CoVLP was evaluated on pregnant rats, embryo-fetal development (EFD), during parturition, lactation and the development of the F1 offspring up to weaning Vaccination with AS03-adjuvanted CoVLP induced an antibody response in F0 females and anti-SARS-CoV-2 spike-specific maternal antibodies were detected in the offspring at the end of the gestation and lactation periods. Overall, there was no evidence of untoward effects of AS03-adjuvanted CoVLP on the fertility or reproductive performance of the vaccinated F0 females. There was no evidence of untoward effects on embryo-fetal development (including teratogenicity), or early (pre-weaning) development of the F1 offspring. These results support the acceptable safety profile of the AS03-adjuvanted CoVLP vaccine for administration to women of childbearing potential.

Evaluating the efficacy of extracted squalene from seed oil in the form of microemulsion for the treatment of COVID-19: A clinical study.

This study investigates the effect of the nanostructure of squalene in the form of microemulsion on COVID-19 patients. In this blinded clinical trial, a comparison was made between the efficacy of squalene treatment and controls. A total of 30 COVID-19 patients admitted to the emergency department, and the infection ward was equally allocated to case (n = 15) and control (n = 15) groups according to their age and underlying diseases. The baseline characteristics of subjects, including age, gender, time of treatment onset, underlying condition, white blood cells count, and lymphocyte count were similar (p < 0.05). Baseline laboratory tests and computed tomography (CT) scans were performed for the study groups. The treatment group received 5 mg of intravenous squalene twice a day and standard treatment for 6 days, while controls received only standard treatment. After 6 days of treatment, clinical and CT scan changes were evaluated and compared in intervention and control groups. The need for oxygen therapy (p = 0.020), 2 days of no fever (p = 0.025), cough alleviation (p = 0.010), and lung high-resolution computed tomography improvement (p = 0.033) were significantly different between cases and controls within 7 days of admission. No adverse effects were observed in the treatment group. Our data suggest that squalene could be considered as a potential treatment for COVID-19, and further studies are required to confirm the results.

Administration of Multivalent Influenza Virus Recombinant Hemagglutinin Vaccine in Combination-Adjuvant Elicits Broad Reactivity Beyond the Vaccine Components.

Combining variant antigens into a multivalent vaccine is a traditional approach used to provide broad coverage against antigenically variable pathogens, such as polio, human papilloma and influenza viruses. However, strategies for increasing the breadth of antibody coverage beyond the vaccine are not well understood, but may provide more anticipatory protection. Influenza virus hemagglutinin (HA) is a prototypic variant antigen. Vaccines that induce HA-specific neutralizing antibodies lose efficacy as amino acid substitutions accumulate in neutralizing epitopes during influenza virus evolution. Here we studied the effect of a potent combination adjuvant (CpG/MPLA/squalene-in-water emulsion) on the breadth and maturation of the antibody response to a representative variant of HA subtypes H1, H5 and H7. Using HA protein microarrays and antigen-specific B cell labelling, we show when administered individually, each HA elicits a cross-reactive antibody profile for multiple variants within the same subtype and other closely-related subtypes (homosubtypic and heterosubtypic cross-reactivity, respectively). Despite a capacity for each subtype to induce heterosubtypic cross-reactivity, broader coverage was elicited by simply combining the subtypes into a multivalent vaccine. Importantly, multiplexing did not compromise antibody avidity or affinity maturation to the individual HA constituents. The use of adjuvants to increase the breadth of antibody coverage beyond the vaccine antigens may help future-proof vaccines against newly-emerging variants.

Enhanced immunity and hemocytes proliferation by three immunostimulants in tri-spine horseshoe crab Tachypleus tridentatus.

Tachypleus amebocyte lysate (TAL) is crucial in medical testing, but its industry in China has been restricted due to the decline of horseshoe crab population in recent years. Exploring methods of enhancing immunity and rapid hemocytes proliferation is urgent for the industrial horseshoe crab culture. In this study, ß-glucan (G), peptidoglycan (P), and squalene (S) were injected to horseshoe crabs at two concentrations (5 and 10 mg/kg), in order to compare their effects on total hemocyte count (THC), reactive oxygen species (ROS), and non-specific immune enzyme activities. Results showed that the THC, superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (T-AOC) were significantly increased by three immunostimulants at different points of time; ROS was significantly increased except at two squalene groups; lysozyme (LZM) and alkaline phosphatase (AKP) activity were increased except at low dose (5 mg/kg) squalene group; malondialdehyde (MDA) activity was decreased in all treatments; and hemocyanin concentration (HC) changed little during the experiment. At the 48th hour, THC, ROS, SOD, CAT, T-AOC, LZM, and AKP activities were significantly higher in the two peptidoglycan groups than those in the control group; the low dose ß-glucan and squalene groups showed significantly higher SOD and CAT, but their THC and AKP were not significantly different from those of the control group. In general, all three immunostimulants stimulated the hemolymph parameters of horseshoe crabs, notably, peptidoglycan could significantly increase the THC and enzyme activities, suggesting that peptidoglycan can be developed as an efficient immunostimulant for horseshoe crabs.

Squalene nanoemulsion reinforces mucosal and immunological fingerprints following intravaginal delivery.

This study describes the assessment of mucosal adjuvant activity of a squalene-based nanoemulsion (SQ@NE) following intravaginal delivery in mice. After immunization, a high level of recruitment of CD11b/c+ granulocytes and F4/80+ macrophages was observed in the vaginal mucosal tissues of the mice immunized with a model protein ovalbumin (OVA) formulated with SQ@NE, and then downstream regulated the expression of MHC II and costimulatory molecules CD40 and CD86 on CD11c+ cells harvested from the associated draining lymph node. With respect to cytotoxic T lymphocyte immunity, the mice immunized with SQ@NE-formulated OVA elicited a high population of OVA-specific CD8+ cells in the spleen and increased the secretion of IFN-γ, IL-2 and IL-17 from OVA-restimulated splenocytes compared with those immunized with OVA alone. By studying in vivo fluorescence imaging and B-cell immunoassays, we discovered how SQ@NE prolongs the retention of antigen depots at the mucosal membrane of the immune inductive site and allows them to properly drive the production of antibodies. The data demonstrated that SQ@NE prolonged fluorescence-labeled OVA retention at the genital tract and augmented the production of OVA-specific IgG in sera and IgA in vaginal washes. These results indicate that SQ@NE is a promising vaginal adjuvant for the induction of both mucosal and systemic immune responses, a feature that provides implications for the development of a mucosal vaccine against genital infections and sexually transmitted diseases.

Immune induction by adjuvanted Leishmania donovani vaccines against the visceral leishmaniasis in BALB/c mice.

Visceral leishmaniasis (VL) is a neglected tropical disease caused by Leishmania donovani or Leishmania infantum. Currently, the patients are treated with chemotherapeutic drugs; however, their toxicity limits their use. It would be desirable to develop a vaccine against this infection. In this study, we assessed the efficacy of different vaccine formulations at variable time points. Heat-killed (HK) antigen of Leishmania donovani was adjuvanted with two adjuvants (AddaVax and Montanide ISA 201) and three immunizations at a gap of 2 weeks (wk) were given to BALB/c mice. After 2 weeks of the last booster, mice were given challenge infection and sacrificed before challenge and after 4wk, 8wk, and 12 wk post-challenge. Significant protective immunity was observed in all the immunized animals and it was indicated by the notable rise in delayed-type hypersensitivity (DTH) response, remarkably declined parasite burden, a significant increase in the levels of interferon-gamma (IFN-γ), interleukin-12, interleukin-17 (Th1 cytokines), and IgG2a in contrast to infected control mice. Montanide ISA 201 with HK antigen provided maximum protection followed by AddaVax with HK and then HK alone. These findings elaborate on the importance of the tested adjuvants in the vaccine formulations against murine visceral leishmaniasis.

IgA binds to the AD-2 epitope of glycoprotein B and neutralizes human cytomegalovirus.

Human cytomegalovirus (HCMV) is a ubiquitous pathogen that is potentially pathogenic in immunosuppressed individuals and pregnant females during primary infection. The HCMV envelope glycoprotein B (gB) facilitates viral entry into all cell types and induces a potent immune response. AD-2 epitope is a highly conserved linear neutralizing epitope of gB and a critical target for antibodies; however, only 50% of sero-positive individuals make IgG antibodies to this site and IgA responses have not been fully investigated. This study aimed to compare IgG and IgA responses against gB and the AD-2 epitope in naturally exposed individuals and those receiving a recombinant gB/MF59 adjuvant vaccine. Thus, vaccination of sero-positive individuals improved pre-existing gB-specific IgA and IgG levels and induced de novo gB-specific IgA and IgG responses in sero-negative recipients. Pre-existing AD-2 IgG and IgA responses were boosted with vaccination, but de novo AD-2 responses were not detected. Naturally exposed individuals had dominant IgG responses towards gB and AD-2 compared with weaker and variable IgA responses, although a significant IgA binding response to AD-2 was observed within human breastmilk samples. All antibodies binding AD-2 contained kappa light chains, whereas balanced kappa/lambda light chain usage was found for those binding to gB. V region-matched AD-2-specific recombinant IgG and IgA bound both to gB and to AD-2 and neutralized HCMV infection in vitro. Overall, these results indicate that although human IgG responses dominate, IgA class antibodies against AD-2 are a significant component of human milk, which may function to protect neonates from HCMV.

Dietary Squalene Induces Cytochromes Cyp2b10 and Cyp2c55 Independently of Sex, Dose, and Diet in Several Mouse Models.

SCOPE: To investigate the effects of squalene, the main hydrocarbon present in extra virgin olive oil, on liver transcriptome in different animal models and to test the influence of sex on this action and its relationship with hepatic lipids. METHODS AND RESULTS: To this purpose, male C57BL/6J Apoe-deficient mice are fed a purified Western diet with or without squalene during 11 weeks and hepatic squalene content is assessed, so are hepatic lipids and lipid droplets. Hepatic transcriptomic changes are studied and confirmed by RT-qPCR. Dietary characteristics and influence of squalene doses are tested in Apoe-deficient on purified chow diets with or without squalene. These diets are also given to Apoa1 and wild-type mice on C57BL/6J background and to C57BL/6J xOla129 Apoe-deficient mice. Squalene supplementation increases its hepatic content without differences among sexes and hormonal status. The Cyp2b10 and Cyp2c55 gene expressions are significantly up-regulated by the squalene intake in all models, with independence of sex, sexual hormones, dietary fat content, genetic background and dose, and in Apoe-deficient mice consuming extra-virgin olive oil. CONCLUSION: Hepatic squalene increases the expression of these cytochromes and their changes in virgin olive oil diets may be due to their squalene content.

Squalene-based multidrug nanoparticles for improved mitigation of uncontrolled inflammation in rodents.

Uncontrolled inflammatory processes are at the root of numerous pathologies. Most recently, studies on confirmed COVID-19 cases have suggested that mortality might be due to virally induced hyperinflammation. Uncontrolled pro-inflammatory states are often driven by continuous positive feedback loops between pro-inflammatory signaling and oxidative stress, which cannot be resolved in a targeted manner. Here, we report on the development of multidrug nanoparticles for the mitigation of uncontrolled inflammation. The nanoparticles are made by conjugating squalene, a natural lipid, to adenosine, an endogenous immunomodulator, and then encapsulating α-tocopherol, as antioxidant. This resulted in high drug loading, biocompatible, multidrug nanoparticles. By exploiting the endothelial dysfunction at sites of acute inflammation, these multidrug nanoparticles delivered the therapeutic agents in a targeted manner, conferring survival advantage to treated animals in models of endotoxemia. Selectively delivering adenosine and antioxidants together could serve as a novel therapeutic approach for safe treatment of acute paradoxal inflammation.

Clinical phase II and III studies of an AS03-adjuvanted H5N1 influenza vaccine produced in an EB66® cell culture platform.

BACKGROUND: We have developed an AS03-adjuvanted H5N1 influenza vaccine produced in an EB66® cell culture platform (KD-295). OBJECTIVES: In accordance with Japanese guidelines for development of pandemic prototype vaccines, the phase II study was conducted in a double-blind, randomized, parallel-group comparison study and the phase III study was conducted in an open-label, non-randomized, uncontrolled study. METHODS: Healthy adult volunteers aged 20 - 64 years enrolled in the phase II and III studies (N = 248 and N = 369) received KD-295 intramuscularly twice with a 21-day interval. After administration, immune response and adverse events were evaluated. In the phase II study, four different vaccine formulations were compared: MA (3.75 µg hemagglutinin [HA] antigen + AS03 adjuvant system), MB (3.75 µg HA + 1/2AS03), HA (7.5 µg HA + AS03), and HB (7.5 µg HA + 1/2AS03). In the phase III study, the MA formulation was further evaluated. RESULTS: In the phase II study, all four vaccine formulations were well-tolerated and no SAE related to vaccination were observed. The MA formulation was slightly more immunogenic and less reactogenic among the vaccine formulations. Therefore, the MA formulation was selected for the phase III study, and it was well-tolerated and no serious adverse drug reactions were observed. The vaccine fulfilled the three immunogenicity criteria described in the Japanese guidelines. CONCLUSIONS: These data indicate that the MA formulation of KD-295 was well-tolerated and highly immunogenic and it can be considered a useful pandemic and pre-pandemic influenza vaccine.

Immunogenicity and Safety of an MF59-adjuvanted Quadrivalent Seasonal Influenza Vaccine in Young Children at High Risk of Influenza-associated Complications: A Phase III, Randomized, Observer-blind, Multicenter Clinical Trial.

BACKGROUND: Vaccination against seasonal influenza is recommended for all children with a history of medical conditions placing them at increased risk of influenza-associated complications. The immunogenicity and efficacy of conventional influenza vaccines among young children are suboptimal; one strategy to enhance these is adjuvantation. We present immunogenicity and safety data for an MF59-adjuvanted quadrivalent influenza vaccine (aIIV4) in healthy children and those at a high risk of influenza-associated complications, based on the results of a recently completed phase III study. METHODS: Children 6 months to 5 years of age (N = 10,644) were enrolled. The study was conducted across northern hemisphere seasons 2013-2014 and 2014-2015. Subjects received either aIIV4 or a nonadjuvanted comparator influenza vaccine. Antibody responses were assessed by hemagglutination inhibition assay against vaccine and heterologous strains. Long-term antibody persistence was assessed (ClinicalTrials.gov: NCT01964989). RESULTS: aIIV4 induced significantly higher antibody titers than nonadjuvanted vaccine in high-risk subjects. aIIV4 antibody responses were of similar magnitude in high-risk and healthy subjects. Incidence of solicited local and systemic adverse events (AEs) was slightly higher in aIIV4 than nonadjuvanted vaccinees, in both the healthy and high-risk groups. Incidence of unsolicited AEs, serious AEs and AEs of special interest were similar for adjuvanted and nonadjuvanted vaccinees in the healthy and high-risk groups. CONCLUSION: aIIV4 was more immunogenic than nonadjuvanted vaccine in both the healthy and high-risk study groups. The reactogenicity and safety profiles of aIIV4 and the nonadjuvanted vaccine were acceptable and similar in 6-month- to 5-year-old high-risk and healthy children.

IgG Fc sialylation is regulated during the germinal center reaction following immunization with different adjuvants.

BACKGROUND: Effector functions of IgG Abs are regulated by their Fc N-glycosylation pattern. IgG Fc glycans that lack galactose and terminal sialic acid residues correlate with the severity of inflammatory (auto)immune disorders and have also been linked to protection against viral infection and discussed in the context of vaccine-induced protection. In contrast, sialylated IgG Abs have shown immunosuppressive effects. OBJECTIVE: We sought to investigate IgG glycosylation programming during the germinal center (GC) reaction following immunization of mice with a foreign protein antigen and different adjuvants. METHODS: Mice were analyzed for GC T-cell, B-cell, and plasma cell responses, as well as for antigen-specific serum IgG subclass titers and Fc glycosylation patterns. RESULTS: Different adjuvants induce distinct IgG+ GC B-cell responses with specific transcriptomes and expression levels of the α2,6-sialyltransferase responsible for IgG sialylation that correspond to distinct serum IgG Fc glycosylation patterns. Low IgG Fc sialylation programming in GC B cells was overall highly dependent on the Foxp3- follicular helper T (TFH) cell-inducing cytokine IL-6, here in particular induced by water-in-oil adjuvants and Mycobacterium tuberculosis. Furthermore, low IgG Fc sialylation programming was dependent on adjuvants that induced IL-27 receptor-dependent IFN-γ+ TFH1 cells, IL-6/IL-23-dependent IL-17A+ TFH17 cells, and high ratios of TFH cells to Foxp3+ follicular regulatory T cells. Here, the 2 latter were dependent on M tuberculosis and its cord factor. CONCLUSION: This study's findings regarding adjuvant-dependent GC responses and IgG glycosylation programming may aid in the development of novel vaccination strategies to induce IgG Abs with both high affinity and defined Fc glycosylation patterns in the GC.

Recombinant Erns-E2 protein vaccine formulated with MF59 and CPG-ODN promotes T cell immunity against bovine viral diarrhea virus infection.

To obtain an effective vaccine candidate against bovine viral diarrhea virus (BVDV) disease which causes great economical loss in cattle industries, recombinant Erns-E2 protein vaccine containing MF59 and CPG-ODN adjuvants was prepared and assessed in this study. The recombinant plasmid (pET32a-Erns-E2) was constructed and transformed into BL21 (DE3) cells to produce Erns-E2 protein. We immunized mice with the MF59-and CPG-ODN-adjuvanted recombinant Erns-E2 protein, E2 protein, or Erns protein, respectively. To evaluate immunogenicity and efficacy of a vaccine-adjuvant combination, mice were challenged with BVDV BJ175170 strain after immunization. All adjuvanted vaccines elicited detectable humoral and cellular immune responses, the BVDV-specific antibody titers as well as interleukin 4 (IL-4) levels in sera of mice immunized with the recombinant Erns-E2 protein were higher than in those of mice immunized with either the recombinant Erns or E2 protein. Besides, immunization with the Erns-E2 vaccines induced higher percentage of CD4+IFN-γ+, CD8+IFN-γ+ T cells and CD3+TNF-α+ T cells compared with the other vaccines. More protective efficacy against BVDV infection was acquired in the mice treated with the recombinant Erns-E2 protein, as shown by a reduction of viremia and slight pathological changes compared with both the control mice and the other vaccinated mice. Our findings suggest that the use of the recombinant Erns-E2 protein vaccine formulated with MF59 and CPG-ODN adjuvants enhances T cell responses and viral control, which warrants the Erns-E2 protein vaccine-adjuvant combination could be as a vaccine strategy to against BVDV.