Advancements in Vaccine Adjuvants: The Journey from Alum to Nano Formulations

A progress report in advancements of heterocyclic compounds as novel antimalarial agents over the last 5 years

Malaria, caused by Plasmodium parasites and transmitted by Anopheles mosquitoes, remains a significant global health challenge, especially in tropical and subtropical regions where the disease is endemic. The complex Plasmodium lifecycle, involving stages in both the liver and bloodstream, leads to symptoms such as high fever, anemia, and, in severe cases, life-threatening complications, particularly P. falciparum infections. While historical treatments such as quinine and modern therapies such as artemisinin-based combination therapies (ACTs) have been effective, the growing issue of drug and insecticide resistance undermines these efforts. This resistance has spurred the need for new antimalarial drugs and strategies. Among the promising areas of research are heterocyclic compounds, which, due to their diverse and versatile chemical structures, are being investigated for their ability to disrupt the Plasmodium lifecycle. These compounds have potential as novel therapeutic agents that could enhance current treatment options. Understanding the mechanisms underlying drug resistance and advancing these therapeutic innovations are crucial for maintaining effective malaria control and treatment, highlighting the importance of on-going research in this field.

Investigation the Concentration Levels of Essential and Non-Essential Elements in Veterinary Vaccines by Inductively Coupled Plasma Mass Spectrometry

Vaccination is one of the cutting-edge approaches for preventing and controlling infectious diseases in humans and animals. However, using elements as mineral adjuvants in vaccine manufacture has raised a vaccine safety concern. This study was designed to determine the concentrations of 19 elements in 33 veterinary vaccines and their diluents given to poultry, pets such as cats and dogs, and large animals including sheep, goats, cattle, and camels using inductively coupled plasma mass spectrometry (ICP-MS) to track these sources of these elements by analyzing vaccines and their diluents. The findings in this study indicated that pet vaccines had a high concentration of all targeted elements, and all analyzed samples were rich in the most vital elements for animals, with particularly high concentrations of Ca. In addition, the results indicate that the majority of elements including Ca, Cr, Mn, Co, Ni, Cu, Zn, Bi, Th, U, Cd, In, and Pb originate from the vaccination diluents. Conversely, antigens are the source of Li, Ga, Sr, and Ba. The study demonstrated the use of Al and Ca as an adjuvant through their high concentrations of both elements in vaccines. The relative standard deviation values (RSD %) were < 4% for all targeted elements, R2 > 0.996, and accuracy % varies between 93% (for 88Sr, and 209Bi) and 99% (for most elements). Research and monitoring to assess the safety and efficacy of elements in veterinary vaccines should be expanded and highlighted to guide future use of these ingredients.

Necrotic enteritis in chickens: a comprehensive review of vaccine advancements over the last two decades

ABSTRACTNecrotic enteritis (NE) is a severe gastrointestinal disease that poses a significant threat to poultry, leading to progressive deterioration of the small intestine, reduced performance, and increased mortality rates, causing economic losses in the poultry industry. The elimination of antimicrobial agents from chicken feed has imposed a need to explore alternative approaches for NE control, with vaccination emerging as a promising strategy to counteract the detrimental consequences associated with NE. This comprehensive review presents an overview of the extensive efforts made in NE vaccination from 2004 to 2023. The review focuses on the development and evaluation of vaccine candidates designed to combat NE. Rigorous evaluations were conducted in both experimental chickens and broiler chickens, the target population, to assess the vaccines' capacity to elicit an immune response and provide substantial protection against toxin challenges and experimental NE infections. The review encompasses the design of vaccine candidates, the antigens employed, in vivo immune responses, and the efficacy of these vaccines in protecting birds from experimental NE infection. This review contributes to the existing knowledge of NE vaccination strategies, offering valuable insights for future research and development in this field.

Impaired Hepatitis B and COVID-19 vaccination responses show strong concordance in hemodialysis patients with end stage renal disease

BACKGROUND

Patients with end stage renal disease (ESRD) undergoing hemodialysis are at increased risk for infection and impaired vaccination responses. We analyzed overlap and influencing factors of vaccination responses against severe acute respiratory syndrome corona virus disease 2 (SARS-CoV-2) and Hepatitis B virus (HBV).

METHODS

SARS-CoV-2 and HBV vaccination response was assessed in a cohort of German ESRD hemodialysis patients. Anti-HBs- and SARS-CoV-2 anti-S-IgG were analyzed by ELISA. Demographic and clinical data were extracted from clinical files.

RESULTS

Sixty-four patients with complete information on HBV and SARS-CoV-2 vaccination responses were included. More than one-third (35.4%) of non-responders upon HBV vaccination were identified. Unresponsiveness after HBV and poor response after SARS-CoV-2 vaccination showed strong overlap, and overall, 70.3% of patients were classified into concordant HBV/SARS vaccination response groups. HBV vaccination non-responsiveness, but not poor SARS-CoV-2 post-vaccination immunity was associated with obesity, while poor SARS-CoV-2 vaccination responses were associated increased age.

CONCLUSION

Our findings confirm previous reports on impaired vaccination response in hemodialysis patients and show that post-vaccination humoral responses against SARS-CoV-2 and HBV display strong overlap in this vulnerable patient group. These results may help to adapt vaccination strategies in this highly vulnerable population.

TRIAL REGISTRATION

German Clinical Trial Registry, DRKS00021152.

Unilateral Anterior Scleritis Following the Booster Shot of Inactivated COVID-19 (Sinopharm) Vaccine in a 52-Year-Old Woman: A Case Report

The only way to mitigate the spread of coronavirus disease 2019 (COVID-19) pandemic was vaccines. While effective in decreasing the rate and severity of the disease, there also have been considerable adverse events. Since the birth of vaccines, adverse reactions accompanied the immunity, and COVID-19 vaccines are no exceptions. This is a report about a 52-year-old female patient who presented with bilateral redness of the eyes, with normal bilateral visual acuity, postbooster dose of the Sinopharm COVID-19 vaccine. She had no significant past history of any disease or any similar reactions after previous doses. All her physical examinations were normal. Ophthalmic examination disclosed diffuse erythema, and mild scleral edema consistent with bilateral anterior diffused scleritis with negative phenylephrine test. Thereafter, with a course of tapering doses of prednisolone (30 mg at the onset) combined with azathioprine (100 mg/day), over a 2-week period, the condition completely resolved. Very few vaccination-related adverse events may manifest an unrecognized underlying autoimmune vasculopathy which may also require urgent management. As in this case, ocular adverse events, as highlighted, are highly associated with undiagnosed autoimmune diseases and therefore warrant careful assessment by clinicians.

Structural analysis and adjuvant activity of a polysaccharide from Urtica macrorrhiza

Developing new vaccine adjuvants for clinical use remains a significant challenge. Herein, we reported a polysaccharide (UMRG) from Urtica macrorrhiza. It has a molecular weight of 743.35 kDa and is composed of rhamnose (Rha), glucuronic acid (GlcA), galacturonic acid (GalA), and galactose (Gal) in a molar ratio of 1.94: 1.00: 4.17: 1.79. Structural analysis revealed that UMRG contains a rhamnogalacturonan I backbone with short side chains of β-Galp-(1→4)-β-GlcAp-(1→4)-β-Glap-(1→ linked at the C-4 position of →2,4)-α-Rhap-(1→. In vivo, UMRG significantly increased the production of antigen-specific IgG, IgG1, and IgG2a by 1.91-, 2.09-, and 3.43-fold, respectively, on day 42 post-immunization. It also promoted the proliferation of splenic lymphocytes, increasing the proportion of CD3+ and CD3+CD4+ T lymphocytes from 32.63 ± 1.13 % to 38.13 ± 2.03 % and from 21.05 ± 0.93 % to 24.34 ± 1.21 %, respectively. Further investigation demonstrated that UMRG promoted the phagocytosis of antigens by dendritic cells, improved their maturation, and stimulated the secretion of the cytokines TNF-α, IL-12, and IL-6. Additionally, both in vitro and in vivo experiments demonstrated that UMRG displayed good biosafety. Our results suggested the Urtica macrorrhiza polysaccharide may exhibit the potential to be developed as a highly efficient and low-toxicity immune adjuvant.

ASIA Syndrome: State-of-the-Art and Future Perspectives

The expression "Autoimmune/inflammatory syndrome induced by adjuvants (ASIA)" was coined by Shoenfeld and colleagues in 2011. It defines a group of immune-mediated disorders that arise in people, with a genetic predisposition, following exposure to adjuvant agents. This syndrome has been reported after contact with silicone implants, medications, infections, metals, vaccines, and other substances. It typically occurs in individuals with a genetic predisposition, particularly involving genes, such as HLA-DRB1 (major histocompatibility complex, class II, DR beta 1) and PTPN22 (protein tyrosine phosphatase non-receptor type 22). Some stimuli lead to an overactivation of the immune system, prompt the production of autoantibodies, and finally cause autoimmune disorders. This narrative review aims to provide an overview of the ASIA syndrome with a special focus on the role of adjuvants in different vaccines, especially after the COVID-19 pandemic, and insights into development of new treatments.

Role of Adjuvants in Enhancing the Efficacy and Duration of Anesthesia Blocks: A Comprehensive Review

Anesthesia blocks are integral to modern pain management, offering targeted and effective relief for various surgical and procedural interventions. These techniques, including regional and peripheral nerve blocks (PNBs), involve the administration of local anesthetics to specific body areas, either through epidural, spinal, or direct nerve injections. While effective, incorporating adjuvants, substances added to local anesthetics, can significantly enhance their efficacy and prolong their duration. Adjuvants such as opioids, corticosteroids, alpha-2 agonists, and nonsteroidal anti-inflammatory drugs (NSAIDs) are used to amplify analgesic effects, reduce the need for general anesthesia, and improve postoperative outcomes. This review explores the role of adjuvants in optimizing anesthesia blocks, examining their mechanisms of action, clinical benefits, and safety considerations. Adding adjuvants can lead to enhanced pain control, reduced dosage of local anesthetics, and fewer systemic side effects. By integrating adjuvants into anesthesia practice, clinicians can achieve more precise and sustained pain management, tailoring approaches to individual patient needs and specific procedural demands. This comprehensive review highlights current evidence on using adjuvants, their impact on anesthesia block effectiveness, and future research directions. Understanding the role of adjuvants is crucial for improving patient outcomes and advancing pain management techniques in various surgical settings.

Structure-Activity Relationship Studies in Benzothiadiazoles as Novel Vaccine Adjuvants

Extracellular vesicles (EVs) can transfer antigens and immunomodulatory molecules, and such EVs released by antigen-presenting cells equipped with immunostimulatory functions have been utilized for vaccine formulations. A prior high-throughput screening campaign led to the identification of compound 634 (1), which enhanced EV release and increased intracellular Ca2+ influx. Here, we performed systematic structure-activity relationship (SAR) studies to investigate the scaffold for its potency as a vaccine adjuvant. Synthesized compounds were analyzed in vitro for CD63 reporter activity (a marker for EV biogenesis) in human THP-1 cells, induction of Ca2+ influx, IL-12 production, and cell viability in murine bone-marrow-derived dendritic cells. The SAR studies indicated that the ester functional group was requisite, and the sulfur atom of the benzothiadiazole ring replaced with a higher selenium atom (9f) or a bioisosteric ethenyl group (9h) retained potency. Proof-of-concept vaccination studies validated the potency of the selected compounds as novel vaccine adjuvants.

The Immunomodulatory Function of Assembled Composite Nanopolypeptide Containing Bursal-Derived BP7 (CNPB7) in Promoting the Mucosal Immune Response within Poultry Immunization

Mucosal immunity is the main defense line against respiratory disease pathogens. Newcastle disease and avian infectious bronchitis are common respiratory diseases in poultry. However, the mucosal immune response is not sufficiently activated and thus fails to achieve the ideal immune protection. Therefore, it is important to develop a suitable mucosal immune adjuvant to enhance the immune response of live vaccines. Here, the bursal-derived peptide BP7, β-glucan, and hyaluronic acid were selected as the adjuvant to be assembled into the composite nanopolypeptide adjuvant (CNPB7) with ultrasonic dispersion technology. The results showed that after optimizing assembly conditions, the optimal average particle size of nanoparticle CNPB7 was 514.9 nm and PDI was 0.298. To evaluate the non-specific immune responses of nanoparticle CNPB7, the chickens were immunized only with nanoparticle CNPB7. It was confirmed that nanoparticle CNPB7 enhanced the expression of CD3, CD4, CD80, and CD86 factors in the spleen lymphocyte from the chicken immunized with nanoparticle CNPB7. To investigate the mucosal immune response of nanoparticle CNPB7, the chickens were orally immunized with Newcastle disease virus (NDV)-infectious bronchitis virus (IBV) dual vaccines and CNPB7. The results proved that the levels of immunoglobulin SIgA, IL-4, IFN-γ, and IL-13 in the mucus samples from the respiratory and digestive tract in chicken immunized with nanoparticle CNPB7 and vaccines were significantly increased, compared to that of vaccine control. Finally, it was observed that nanoparticle CNPB7 promoted specific increased antibody productions against NDV and IBV in the immunized chicken. These results proved that the assembled nanoparticle CNPB7 could enhance the vaccination efficacy in chicken, which provided the experimental basis for the development of new adjuvants, and offered technical support for preventing virus transmission of avian diseases.

Immunomodulatory Peptides as Vaccine Adjuvants and Antimicrobial Agents

The underdevelopment of adjuvant discovery and diversity, compared to core vaccine technology, is evident. On the other hand, antibiotic resistance is on the list of the top ten threats to global health. Immunomodulatory peptides that target a pathogen and modulate the immune system simultaneously are promising for the development of preventive and therapeutic molecules. Since investigating innate immunity in insects has led to prominent achievements in human immunology, such as toll-like receptor (TLR) discovery, we used the capacity of the immunomodulatory peptides of arthropods with concomitant antimicrobial or antitumor activity. An SVM-based machine learning classifier identified short immunomodulatory sequences encrypted in 643 antimicrobial peptides from 55 foe-to-friend arthropods. The critical features involved in efficacy and safety were calculated. Finally, 76 safe immunomodulators were identified. Then, molecular docking and simulation studies defined the target of the most optimal peptide ligands among all human cell-surface TLRs. SPalf2-453 from a crab is a cell-penetrating immunoadjuvant with antiviral properties. The peptide interacts with the TLR1/2 heterodimer. SBsib-711 from a blackfly is a TLR4/MD2 ligand used as a cancer vaccine immunoadjuvant. In addition, SBsib-711 binds CD47 and PD-L1 on tumor cells, which is applicable in cancer immunotherapy as a checkpoint inhibitor. MRh4-679 from a shrimp is a broad-spectrum or universal immunoadjuvant with a putative Th1/Th2-balanced response. We also implemented a pathway enrichment analysis to define fingerprints or immunological signatures for further in vitro and in vivo immunogenicity and reactogenicity measurements. Conclusively, combinatorial machine learning, molecular docking, and simulation studies, as well as systems biology, open a new opportunity for the discovery and development of multifunctional prophylactic and therapeutic lead peptides.