Vaxine (Australia)

Jack Jumper ant (JJA) venom immunotherapy (VIT) is highly efficacious but the lowest effective dose is unknown. Delta-inulin adjuvant (Advax) is known to enhance honeybee VIT immunogenicity. This phase 1/2 single-blind, randomised controlled trial aimed to compare the efficacy and safety of JJA VIT with different doses of venom ± Advax. Adults aged 18-65 with a history of immediate systemic reaction (SR) to JJA stings were randomised to receive JJA VIT at a maintenance dose of 25 mcg or 50 mcg ± Advax; participants were blinded to treatment allocation. Primary outcomes were the response to sting challenges after 12 months and venom-specific IgE and IgG4 responses to treatment. Forty-nine of 50 screened subjects met inclusion criteria and were randomised; 44 started treatment (25 mcg n = 12; 25 mcg + Advax n = 13; 50mcg n = 12, 50 mcg + Advax n = 12). Subsequently, two withdrew due to SRs to treatment, and two withdrew due to unrelated factors. The higher JJA venom maintenance dose was associated with reduced likelihood of SRs (OR 0.53 (95% CI, 0.28-0.98)), while Advax did not have an effect (OR 1.17 (95% CI, 0.59-2.32)). Forty proceeded to sting challenge, with six developing SRs. There was no difference between groups for sting challenge outcome (p = 0.98), and the ORs for 25 mcg vs. 50 mcg venom dose (0.89, 95% CI, 0.38-2.09) and Advax vs. no Advax (0.99, 95% CI 0.42-2.33) indicated no effect. There were no differences between groups for venom sIgE (p = 0.78), sIgG4 (p = 0.25), sIgE/IgG4 ratio (p = 0.42), intradermal (p = 0.77), and basophil activation test (BAT) (p = 0.69) responses to treatment. Subjects with high baseline BAT sensitivity, which reduced markedly in response to treatment, were less likely to have a positive sting challenge (p = 0.006). Challenge outcomes were similar for all groups, with no significant difference found between 25 and 50 mcg maintenance dose or between treatment with and without Advax. Further research of low dose JJA VIT is warranted to confirm its efficacy and tolerability. NCT03066986.

Allergen-specific monoclonal antibodies (mAbs) have recently emerged as promising tools in allergy therapy, particularly for patients who do not respond adequately to allergen-specific immunotherapy (AIT). While previous studies have explored systemic delivery routes, the efficacy of local intranasal administration of allergen-specific mAb remains largely unexplored. Artemisia vulgaris pollen is among the top global aeroallergens, strongly associated with seasonal allergic rhinitis and asthma. Hybridoma-derived murine IgG1 mAb specific to A. vulgaris pollen extract were generated and screened in vitro for their ability to block both mouse and human IgE binding to crude pollen extract and its major allergen, Art v 1.A lead mAb candidate was selected for in vivo evaluation using a BALB/c mouse model of allergic airway inflammation. The mAb was administered intranasally one hour prior to each of three consecutive allergen challenges. Clinical symptoms, airway hyperresponsiveness (AHR), lung cytokine profiles, and histopathological changes in nasal and lung tissues were assessed. Five IgG1 mAb recognising A. vulgaris extract were generated, with clone XA19 being the most potent, with high-affinity binding and IgE-blocking activity for both pollen extract (18-22% inhibition) and recombinant Art v 1 protein (52% inhibition). Intranasal pretreatment with XA19 prior to allergen challenge in pre-sensitised mice resulted in significant suppression of the ear swelling response, rhinitis symptoms, AHR, and lung and nasal turbinate inflammation. Pulmonary levels of Th2 cytokines (IL-4 and IL-5) were markedly reduced in mAb-pretreated mice, while total serum IgE levels remained largely unaffected. Intranasal delivery of allergen-specific mAbs represents a novel, non-invasive strategy to prevent both upper and lower airway allergic inflammation. Our findings establish proof-of-concept for this approach and warrant further development.

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

We developed a novel intranasal SARS-CoV-2 subunit vaccine called NARUVAX-C19/Nano based on the spike protein receptor-binding domain (RBD) entrapped in mannose-conjugated chitosan nanoparticles (NP). A toll-like receptor 9 agonist, CpG55.2, was also added as an adjuvant to see if this would potentiate the cellular immune response to the NP vaccine. The NP vaccine was assessed for immunogenicity, protective efficacy, and ability to prevent virus transmission from vaccinated animals to naive cage-mates. The results were compared with a RBD protein vaccine mixed with alum adjuvant and administered intramuscularly. BALB/c mice vaccinated twice intranasally with the NP vaccines exhibited secretory IgA and a pronounced Th1-cell response, not seen with the intramuscular alum-adjuvanted RBD vaccine. NP vaccines protected Syrian hamsters against a wild-type SARS-CoV-2 infection challenge as indicated by significant reductions in weight loss, lung viral load and lung pathology. However, despite significantly reduced viral load in the nasal turbinates and oropharyngeal swabs from NP-vaccinated hamsters, virus transmission was not prevented to naïve cage-mates. In conclusion, intranasal RBD-based NP formulations induced mucosal and Th1-cell mediated immune responses in mice and protected Syrian hamsters against SARS-CoV-2 infection but not against viral transmission.

Toll-like receptors (TLRs) are the pattern recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) in microbial species. Among the various TLRs, TLR2 has a special place due to its ability to sense the widest repertoire of PAMPs owing to its heterodimerization with either TLR1 or TLR6, broadening its ligand diversity against pathogens. Various scaffolds are reported to activate TLR2, which include naturally occurring lipoproteins, synthetic lipopeptides, and small heterocyclic molecules. We described a detailed SAR in TLR2 agonistic scaffolds and also covered the design and chemistry for the conjugation of TLR2 agonists to antigens, carbohydrates, polymers, and fluorophores. The approaches involved in delivery of TLR2 agonists such as lipidation of antigen, conjugation to polymers, phosphonic acids, and other linkers to achieve surface adsorption, liposomal formulation, and encapsulating nanoparticles are elaborated. The crystal structure analysis and computational modeling are also included with the structural features that facilitate TLR2 activation.

This paper reports the oxidation of inulin using varying ratios of sodium periodate and the characterization of the inulin polyaldehyde. The physicochemical properties of the inulin polyaldehyde (oxidized inulin) were characterized using different techniques including 1D NMR spectroscopy, 13C Nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC), ultraviolet-visible spectroscopy (UV), and scanning electron microscopy (SEM). The aldehyde peak was not very visible in the FTIR, because the aldehyde functional group exists in a masked form (hemiacetal). The thermal stability of the oxidized inulin decreased with the increasing oxidation degree. The smooth spherical shape of raw inulin was destructed due to the oxidation, as confirmed by the SEM result. The 1HNMR results show some new peaks from 4.8 to 5.0 as well as around 5.63 ppm. However, no aldehyde peak was found around 9.7 ppm. This can be attributed to the hemiacetal. The reaction of oxidized inulin with tert-butyl carbazate produced a carbazone conjugate. There was clear evidence of decreased peak intensity for the proton belonging to the hemiacetal group. This clearly shows that not all of the hemiacetal group can be reverted by carbazate. In conclusion, this work provides vital information as regards changes in the physicochemical properties of the oxidized inulin, which has direct implications when considering the further utilization of this biomaterial.

BackgroundAlzheimer disease (AD) is characterized by the accumulation of beta-amyloid (Aβ) plaques and neurofibrillary tangles composed of hyperphosphorylated tau, which together lead to neurodegeneration and cognitive decline. Current therapeutic approaches have primarily aimed to reduce pathological aggregates of either Aβ or tau, yet phase 3 clinical trials of these approaches have thus far failed to delay disease progression in humans. Strong preclinical evidence indicates that these two abnormally aggregated proteins interact synergistically to drive downstream neurodegeneration. Therefore, combinatorial therapies that concurrently target both Aβ and tau might be needed for effective disease modification.MethodsA combinatorial vaccination approach was designed to concurrently target both Aβ and tau pathologies. Tau22/5xFAD (T5x) bigenic mice that develop both pathological Aβ and tau aggregates were injected intramuscularly with a mixture of two MultiTEP epitope vaccines: AV-1959R and AV-1980R, targeting Aβ and tau, respectively, and formulated in AdvaxCpG, a potent polysaccharide adjuvant. Antibody responses of vaccinated animals were measured by ELISA, and neuropathological changes were determined in brain homogenates of vaccinated and control mice using ELISA and Meso Scale Discovery (MSD) multiplex assays.ResultsT5x mice immunized with a mixture of Aβ- and tau-targeting vaccines generated high Aβ- and tau-specific antibody titers that recognized senile plaques and neurofibrillary tangles/neuropil threads in human AD brain sections. Production of these antibodies in turn led to significant reductions in the levels of soluble and insoluble total tau, and hyperphosphorylated tau as well as insoluble Aβ42, within the brains of bigenic T5x mice.ConclusionsAV-1959R and AV-1980R formulated with AdvaxCpG adjuvant are immunogenic and therapeutically potent vaccines that in combination can effectively reduce both of the hallmark pathologies of AD in bigenic mice. Taken together, these findings warrant further development of this vaccine technology for ultimate testing in human AD.