Adjuvant effects of saponins on animal immune responses

Vaccines efficacy against infection with circulating feline calicivirus after one single injection: Comparison of Leucofeligen™ FeLV/RCP and Purevax™ RCPFeLV vaccines

Feline calicivirus (FCV) is a worldwide pathogen that affects the general health status of cats. The aim of this study was to assess the efficacy of the FCV component of two multivalent commercial vaccines after one injection. The cats assigned to the vaccinated groups received one subcutaneous injection of either the Leucofeligen™ FeLV/RCP (Virbac, France) vaccine or the Purevax™ RCPFeLV (Boehringer Ingelheim, Germany) vaccine. In the control group, the cats did not receive any vaccine. Three weeks after the vaccine injection, all the cats were inoculated with a heterologous calicivirus strain, isolated in the field. The clinical signs of calicivirosis and the viral shedding were assessed. The results demonstrated that Leucofeligen™ FeLV/RCP could protect kittens against FCV infection by reducing clinical signs and viral excretion from 3 weeks after the first injection of primary vaccination, whereas Purevax™ RCPFeLV couldn't offer the same level of protection in similar experimental conditions.

Vaccine adjuvants: current status, research and development, licensing, and future opportunities

Vaccines represent one of the most significant inventions in human history and have revolutionized global health. Generally, a vaccine functions by triggering the innate immune response and stimulating antigen-presenting cells, leading to a defensive adaptive immune response against a specific pathogen's antigen. As a key element, adjuvants are chemical materials often employed as additives to increase a vaccine's efficacy and immunogenicity. For over 90 years, adjuvants have been essential components in many human vaccines, improving their efficacy by enhancing, modulating, and prolonging the immune response. Here, we provide a timely and comprehensive review of the historical development and the current status of adjuvants, covering their classification, mechanisms of action, and roles in different vaccines. Additionally, we perform systematic analysis of the current licensing processes and highlights notable examples from clinical trials involving vaccine adjuvants. Looking ahead, we anticipate future trends in the field, including the development of new adjuvant formulations, the creation of innovative adjuvants, and their integration into the broader scope of systems vaccinology and vaccine delivery. The article posits that a deeper understanding of biochemistry, materials science, and vaccine immunology is crucial for advancing vaccine technology. Such advancements are expected to lead to the future development of more effective vaccines, capable of combating emerging infectious diseases and enhancing public health.

Recombinant spike protein vaccines coupled with adjuvants that have different modes of action induce protective immunity against SARS-CoV-2

The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a glycoprotein, expressed on the virion surface, that mediates infection of host cells by directly interacting with host receptors. As such, it is a reasonable target to neutralize the infectivity of the virus. Here we found that a recombinant S protein vaccine adjuvanted with Alhydrogel or the QS-21-like adjuvant Quil-A effectively induced anti-S receptor binding domain (RBD) serum IgG and neutralizing antibody titers in the Syrian hamster model, resulting in significantly low SARS-CoV-2 replication in respiratory organs and reduced body weight loss upon virus challenge. Severe lung inflammation upon virus challenge was also strongly suppressed by vaccination. We also found that the S protein vaccine adjuvanted with Alhydrogel, Quil-A, or an AS03-like adjuvant elicited significantly higher neutralizing antibody titers in mice than did unadjuvanted vaccine. Although the neutralizing antibody titers against the variant viruses B.1.351 and B.1.617.2 declined markedly in mice immunized with wild-type S protein, the binding antibody levels against the variant S proteins were equivalent to those against wild-type S. When splenocytes from the immunized mice were re-stimulated with the S protein in vitro, the induced Th1 or Th2 cytokine levels were not significantly different upon re-stimulation with wild-type S or variant S, suggesting that the T-cell responses against the variants were the same as those against the wild-type virus. Upon Omicron XBB-challenge in hamsters, wild-type S-vaccination with Alhydrogel or AS03 reduced lung virus titers on Day 3, and the Quil-A adjuvanted group showed less body weight loss, although serum neutralizing antibody titers against XBB were barely detected in vitro. Collectively, recombinant vaccines coupled with different adjuvants may be promising modalities to combat new variant viruses by inducing various arms of the immune response.

In Vivo Efficacy of Purified Quillaja Saponin Extracts in Protecting against Piscirickettsia salmonis Infections in Atlantic Salmon (Salmo salar)

Piscirickettsiosis, the main infectious disease affecting salmon farming in Chile, still has no efficient control measures. Piscirickettsia salmonis is a facultative intracellular bacterium that can survive and replicate within the host macrophages, evading the immune response. Triterpenic saponins obtained from the Quillaja saponaria tree have been widely studied, and have been shown to be immunomodulatory agents, suitable for feed and vaccine applications for veterinary and human uses. The impact of the oral administration of two extracts of Quillaja saponins on the infection of P. salmonis in Salmo salar and the corresponding gene expressions of immunomarkers were studied under three in vivo models. In the intraperitoneal challenge model, the group fed with Quillaja extracts showed lower mortality (29.1% treated vs. 37.5% control). Similar results were obtained in the cohabitation model trial (36.3% vs. 60.0%). In the commercial pilot trial, the results showed a significant reduction of 71.3% in mortality caused by P. salmonis (0.51% vs. 1.78%) and antibiotic use (reduction of 66.6% compared to untreated control). Also, Quillaja extracts significantly modulated the expression of IFN-II and CD8. These results represent evidence supporting the future use of purified Quillaja extracts as a natural non-pharmacological strategy for the prevention and control of P. salmonis infections in salmon.

Antiaging effects of dietary supplements and natural products

Aging is an inevitable process influenced by genetics, lifestyles, and environments. With the rapid social and economic development in recent decades, the proportion of the elderly has increased rapidly worldwide, and many aging-related diseases have shown an upward trend, including nervous system diseases, cardiovascular diseases, metabolic diseases, and cancer. The rising burden of aging-related diseases has become an urgent global health challenge and requires immediate attention and solutions. Natural products have been used for a long time to treat various human diseases. The primary cellular pathways that mediate the longevity-extending effects of natural products involve nutrient-sensing pathways. Among them, the sirtuin, AMP-activated protein kinase, mammalian target of rapamycin, p53, and insulin/insulin-like growth factor-1 signaling pathways are most widely studied. Several studies have reviewed the effects of individual natural compounds on aging and aging-related diseases along with the underlying mechanisms. Natural products from food sources, such as polyphenols, saponins, alkaloids, and polysaccharides, are classified as antiaging compounds that promote health and prolong life via various mechanisms. In this article, we have reviewed several recently identified natural products with potential antiaging properties and have highlighted their cellular and molecular mechanisms. The discovery and use of dietary supplements and natural products that can prevent and treat multiple aging-related diseases in humans will be beneficial. Thus, this review provides theoretical background for existing dietary supplements and natural products as potential antiaging agents.

Lessons learned from the SARS-CoV-2 pandemic; from nucleic acid nanomedicines, to clinical trials, herd immunity, and the vaccination divide

INTRODUCTION

In November 2019, the idea of a zoonotic virus crossing over to human transmission in a seafood market in Wuhan, China, and then soaring across the globe to claim over 6.3 million lives and persisting to date, seemed more like wild science fiction than a future reality. As the SARS-CoV-2 pandemic continues, it is important to hallmark the imprints the pandemic has made on science.

AREAS COVERED

This review covers the biology of SARS-CoV-2, vaccine formulations and trials, the concept of 'herd resistance,' and the vaccination divide.

EXPERT OPINION

The SARS-CoV-2 pandemic has changed the landscape of medicine. The rapid approval of SARS-CoV-2 vaccines has changed the culture of drug development and clinical approvals. This change is already leading to more accelerated trials. The RNA vaccines have opened the market for nucleic acid therapies and the applications are limitless - from cancer to influenza. A phenomenon that has occurred is that the low efficacy of current vaccines and the rapid mutation rate of the virus is preventing herd immunity from being attained. Instead, herd resistance is being acquired. Even with future, more effective vaccines, anti-vaccination attitudes will continue to challenge the quest for SARS-CoV-2 herd immunity.

Alpha to Omicron (Variants of Concern): Mutation Journey, Vaccines, and Therapy

Coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) initially emerged in December 2019 and has subsequently expanded globally, leading to the ongoing pandemic. The extensive spread of various SARS-CoV-2 variants possesses a serious public health threat. An extensive literature search along with deep analysis was performed to describe and evaluate the characteristics of SARS-CoV-2 variants of concern in relation to the effectiveness of the current vaccines and therapeutics. The obtained results showed that several significant mutations have evolved during the COVID-19 pandemic. The developed variants and their various structural mutations can compromise the effectiveness of several vaccines, escape the neutralizing antibodies, and limit the efficiency of available therapeutics. Furthermore, deep analysis of the available data enables the prediction of the future impact of virus mutations on the ongoing pandemic along with the selection of appropriate vaccines and therapeutics.

Safe Subunit Green Vaccines Confer Robust Immunity and Protection against Mucosal Brucella Infection in Mice

Brucellosis is a zoonotic disease that causes significant negative impacts on the animal industry and affects over half a million people worldwide every year. The limited safety and efficacy of current animal brucellosis vaccines, combined with the lack of a licensed human brucellosis vaccine, have led researchers to search for new vaccine strategies to combat the disease. To this end, the present research aimed to evaluate the safety and efficacy of a green vaccine candidate that combines Brucella abortus S19 smooth lipopolysaccharide (sLPS) with Quillaja saponin (QS) or QS-Xyloglucan mix (QS-X) against mucosal brucellosis in BALB/C mice. The results of the study indicate that administering two doses of either sLPS-QS or sLPS-QS-X was safe for the animals, triggered a robust immune response, and enhanced protection following intranasal challenge with S19. Specifically, the vaccine combinations led to the secretion of IgA and IgG1 in the BALF of the immunized mice. We also found a mixed IgG1/IgG2a systemic response indicating evidence of both Th1 and Th2 activation, with a predominance of the IgG1 over the IgG2a. These candidates resulted in significant reductions in the bioburden of lung, liver, and spleen tissue compared to the PBS control group. The sLPS-QS vaccination had conferred the greatest protection, with a 130-fold reduction in Brucella burdens in lung and a 55.74-fold reduction in the spleen compared to PBS controls. Vaccination with sLPS-QS-X resulted in the highest reduction in splenic Brucella loads, with a 364.6-fold decrease in bacterial titer compared to non-vaccinated animals. The study suggests that the tested vaccine candidates are safe and effective in increasing the animals’ ability to respond to brucellosis via mucosal challenge. It also supports the use of the S19 challenge strain as a safe and cost-effective method for testing Brucella vaccine candidates under BSL-2 containment conditions.

GC/MS and LC/MS Phytochemical Analysis of Vigna unguiculata L. Walp Pod

Vigna unguiculata (L. Walp) or Cowpea pod methanolic extracts phytochemical analysis, total phenolic content (TPC), and secondary metabolite profiling were determined using gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (LC/MS) analysis. GC/MS analysis revealed twenty compounds in the extract, while LC/MS analysis identified twenty-four compounds. GC/MS chromatogram analysis suggested the presence of opioid α-N-Normethadol a major constituent found in methanolic extract and fatty acid esters carotenoid is found second major constituent. LC/MS chromatogram and the mass spectral analysis demonstrated the presence of flavonoids, carotenoids, and alkaloids as major phytochemicals. We investigated the antibacterial, anti-fungal, and anti-oxidant activity of pod methanolic extract. The extract was found equally effective against E. coli, S. pyogenes, and P. aeruginosa with MIC 100 μg/mL similar to the standard Ampicillin (MIC 100 μg/mL). C. albicans were found to be most susceptible to Vign unguiculata pods methanolic extract with a MIC of 250 μg/mL. The pod extract showed significant DPPH scavenging activity (IC₅₀ =78.38±0.15) which suggests its antioxidant potential.

In-vitro evaluation of immunomodulatory activity of sulphation-modified total ginsenosides derivative-3

Background

Ginseng has been used in biomedicine to prevent and treat decreased physical and mental capacities. Total ginsenosides (TG) from ginseng root which have antitumor and immune-enhancing properties, are the principal active components of Panax ginseng, while the sulphation-modified TG derivative-3 (SMTG-d3) was expected to enhance the anticancer activity in conventional medicinal treatments.

Methods

The chlorosulphonic acid-pyridine technique, used for the sulfation modification of TG to improve their biological activity, and the infrared spectroscopic characteristics of TG and SMTG-d3 were investigated, and the effects of SMTG-d3 on immunocytes and cytokines relevant to tumor treatment were assessed. The MTT assay was used to assess the effect of TG and SMTG-d3 on the cytotoxicity and T-lymphocytic proliferation against mouse splenocytes. The LDH method was employed to evaluate NK activity induced by TG or SMTG-d3. The production levels of splenocytes-secreted IL-2 and IFN-γ and peritoneal macrophages-secreted TNF-α were determined using mouse ELISA kits.

Results and discussion

It showed that the ideal conditions for the sulfation modification of TG: the volume ratio of chlorosulfonic acid to pyridine lower than 1:2.5; controlled amount of chlorosulfonic acid; and a yield of 51.5% SMTG-d3 (2 h, < 45°C). SMTG-d3 showed two characteristic absorption peaks at 1,230 cm^-1 and 810 cm^-1, indicating the formation of sulfuric acid esters and the presence of sulfuric acid groups. SMTG-d3 exhibited higher antitumor immunological activity than TG by promoting the proliferation of T lymphocytes and the production of IFN-γ and TNF-α, thus enhancing NK cell activity, and reducing cytotoxicity. The findings imply sulfated modification represents an effective method of enhancing the immunomodulatory activities of TG and could be used as the basis for developing new drug target compounds; SMTG-d3 can serve as an antitumor immunomodulator and can be considered an effective and prospective herbal formulation in clinical applications.

A single dose of Astragalus saponins adjuvanted inactivated vaccine for pseudorabies virus protected mice against lethal challenge

Pseudorabies (PR) is an important infectious disease of swine that causes enormous economic losses to the swine industry in China. Immunization with vaccines is a routine practice to control this disease. PRV inactivated vaccines usually require a booster vaccination to provide complete immune protection. Therefore, Astragalus saponins (AST) have been added as an immunopotentiator to improve the immune efficacy and reduce the immunization times for the PRV inactivated vaccine. The results in mice have shown that a single dose of AST-adjuvanted PRV inactivated vaccine promoted higher production of gB-specific IgG, IgG1, and IgG2a and neutralizing antibody, secretion of Th1-type (IFN-γ) and Th2-type (IL-4) cytokines, and lymphocyte proliferation than mice immunized without AST. Compared to mice immunized without AST, a single dose of the AST-adjuvanted PRV inactivated vaccine improved the survival percentage of mice and reduced the PRV viral loads in the lungs and brains after lethal challenge. In summary, AST was an effective immunopotentiator to improve the immune efficacy of a single dose PRV inactivated vaccine.

Development of Foot-and-Mouth Disease Vaccines in Recent Years

Foot-and-mouth disease (FMD) is a serious disease affecting the global graziery industry. Once an epidemic occurs, it can lead to economic and trade stagnation. In recent decades, FMD has been effectively controlled and even successfully eradicated in some countries or regions through mandatory vaccination with inactivated foot-and-mouth disease vaccines. Nevertheless, FMD still occurs in some parts of Africa and Asia. The transmission efficiency of foot-and-mouth disease is high. Both disease countries and disease-free countries should always be prepared to deal with outbreaks of FMD. The development of vaccines has played a key role in this regard. This paper summarizes the development of several promising vaccines including progress and design ideas. It also provides ways to develop a new generation of vaccines for FMDV and other major diseases.

Modulation of immunological responses by aqueous extract of Datura stramonium L. seeds on cyclophosphamide-induced immunosuppression in Wistar rats

BACKGROUND

Datura stramonium L. (Solanaceae) is used traditionally in west Africa to treat asthma, epilepsy, rheumatoid arthritis, filariasis microbial infections and conjunctivitis. This study investigated the immunomodulatory effects of aqueous seed extract of D. stramonium L. (ASEDS) on Wistar rats.

METHODS

Thirty Wistar albino rats (180-200 g) were randomized into 6 groups (n = 5). Group 1 received distilled water only. Rats in groups 2-6 were pretreated with 10 mg/kg body weight (b.w.) Cyclophosphamide orally for 27-days to induce immunosuppression. Thereafter, they received treatment orally for 28 days as follows: Group 2 (distilled water), group 3 (5 mg/kg b.w. Levamisole), groups 4-6 (60, 90 and 120 mg/kg b.w. ASEDS, respectively). HPLC was used to determine major compounds in ASEDS. The effects of ASEDS on immune cells, immunoglobulins A, G and M levels, lipoproteins, and antioxidant status of rats were evaluated.

RESULTS

ASEDS indicated high content of Acutumine, Quinine, Catechin, Chlorogenic acid, Gallic acid, Quercetin, Vanillic acid, Luteolin, Formosanin C, Saponin, Cyanidin, Tannic acid, 3-Carene, Limonene and α-terpineol. Cyclophosphamide triggered significant (p < 0.05) reduction in total leucocyte count and differentials, IgA, IgG, high-density lipoproteins (HDL), catalase, superoxide dismutase, glutathione peroxidase, vitamins A, C and E levels of untreated rats. Administration of ASEDS led to significant (p < 0.05) improvement in immune cell counts, immunoglobulin synthesis, high-density lipoprotein concentration, and antioxidant status of rats in the treated groups.

CONCLUSIONS

The results obtained from the study showed the immunomodulatory activity of ASEDS, thereby indicating its potential in immunostimulatory drug discovery.

EEHV1A glycoprotein B subunit vaccine elicits humoral and cell-mediated immune responses in mice

Asian elephants are an endangered species facing many threats, including severe hemorrhagic disease (HD) caused by the elephant endotheliotropic herpesvirus (EEHV). EEHV-HD is the leading cause of death in captive juvenile Asian elephants in North America and Europe, and also affects elephants in their natural range countries. Significant challenges exist for successful treatment of EEHV-HD, which include timely recognition of disease onset and limited availability of highly effective treatment options. To address this problem, our goal is to prevent lethal disease in young elephants by developing a vaccine that elicits robust and durable humoral and cell-mediated immunity against EEHV. EEHV glycoprotein B (gB) is a major target for cellular and humoral immunity in elephants previously exposed to EEHV. Therefore, we generated a vaccine containing recombinant EEHV1A gB together with a liposome formulated TLR-4 and saponin combination adjuvant (SLA-LSQ). CD-1 mice that received one or two vaccinations with the vaccine elicited significant anti-gB antibody and polyfunctional CD4⁺ and CD8⁺ T cell responses, while no adverse effects of vaccination were observed. Overall, our findings demonstrate that an adjuvanted gB protein subunit vaccine stimulates robust humoral and cell-mediated immune responses and supports its potential use in elephants.

Two Species Origins Comparison of Herba Patriniae based on Their Ingredients Profile by UPLC-QTOF/MS/MS and Orthogonal Partial Least Squares Discriminant Analysis

Herba Patriniae (HP) is widely used as a medicinal and edible material in China. Besides food value, HP attracts more attention due to its medicinal potential. Patrinia villosa Juss. ( PV ) and Patrinia scabiosaefolia Fisch. ( PS ) are the two species origins of HP. These two of HP show different effects on cell proliferation, migration, angiogenesis and anti-diabetic. As we have previously reported, PV and PS show significant differences on their anti-inflammatory ability in the same experimental model. Comparing the ingredient profiles of two different sources will not only facilitate the understanding of their medicinal effects, but also help the development and research of new activities. However, still now, there is no systematic and detailed study to compare the components of PV and PS . In present study, ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was employed to achieve a high-throughput qualitative and thorough analysis of the chemical composition spectrum of HP. A total of 164 compounds were identified, among these compounds, 127 compounds were identified from PV , and 107 compounds were identified from PS . Most of the chemical components was discovered for the first time. Flavonoids, saponins, terpenoids and organic acids, as the main ingredients in PV and PS were 45.45%vs 28.46%, 12.61% vs 32.09%, 14.33% vs 22.38% and 14.58% vs 6.79%, respectively. Flavonoids are the main components of PV , while PS is rich in saponins. PV and PS were classified into two groups by principal component analysis (PCA) and screened out the main molecular differences responsible by orthogonal partial least squares discriminant analysis (OPLS-DA). All the results will be a guide for the quality control, functional activity research, or better clinic use based on the ingredients profile between these two species. Besides, this first study on ingredients profile of two species origins will be beneficial for potential and best resources utilization of both PV and PS .

Immune and Oxidative Response against Sonicated Antigen of Mycoplasma capricolum subspecies capripneumonia-A Causative Agent of Contagious Caprine Pleuropneumonia

Vaccines are vital for prevention and control of mycoplasma diseases. The exploration of a vaccine candidate for the development of a vaccine is imperative. The present study envisages the evaluation of immune and oxidative response against an adjuvanted, sonicated antigen of Mycoplasma capricolum subsp. capripneumonia in male Angora rabbits (1 year old, 2 kg) divided in four groups, each having six animals. Group 1 was the healthy control and received 1 mL PBS via subcutaneous route. Group 2 was administered 1 mL of saponin-adjuvanted and -sonicated antigen, Group 3 was given 1 mL of montanide ISA 50-adjuvanted and-sonicated antigen, and Group 4 was given 1 mL of standard vaccine via subcutaneous route. Animals were evaluated for cellular and humoral immune response and oxidative parameters at 0, 7, 14, 21, and 28 days of the study. Total leukocytic, neutrophilic, and basophilic counts showed a significant (p < 0.05) increase in vaccinated groups compared to the healthy group on most of the intervals. TNF-α levels were significantly (p < 0.05) higher in the Group 2 than the Group 1 at all the time intervals and more comparable to Group 4 than Group 3. IL-10 levels were significantly (p < 0.05) higher in vaccinated groups compared to the healthy group on days 14, 21, and 28, but were lower in Group 3 than in Group 2 and Group 4. More hypersensitivity as inflammation and histopathological cellular infiltration in the ear was produced in Group 2 and Group 4 than in Group 3. IgG levels were significantly (p < 0.05) higher in Group 2 and Group 4 than in Group 3 on days 14 and 21. Antibody titers were comparatively higher in Group 4, followed by Group 2 and 3, than Group 1. Significantly (p < 0.05) higher oxidant and lower antioxidant values were noted in Group 2 and 4 compared to Group 3 and Group 1 on most of the intervals. The TLC and antibody titer showed increasing trend throughout the trial, whereas TNF-α, IgG, L, M and E started decreasing from day 14, and IL-10, N and B started decreasing from day 21. This study concludes that the saponin-adjuvanted and-sonicated antigen induces comparatively higher immune response than montanide but is associated with oxidative and inflammatory reactions.

Advances in Infectious Disease Vaccine Adjuvants

Vaccines are one of the most significant medical interventions in the fight against infectious diseases. Since their discovery by Edward Jenner in 1796, vaccines have reduced the worldwide transmission to eradication levels of infectious diseases, including smallpox, diphtheria, hepatitis, malaria, and influenza. However, the complexity of developing safe and effective vaccines remains a barrier for combating many more infectious diseases. Immune stimulants (or adjuvants) are an indispensable factor in vaccine development, especially for inactivated and subunit-based vaccines due to their decreased immunogenicity compared to whole pathogen vaccines. Adjuvants are widely diverse in structure; however, their overall function in vaccine constructs is the same: to enhance and/or prolong an immunological response. The potential for adverse effects as a result of adjuvant use, though, must be acknowledged and carefully managed. Understanding the specific mechanisms of adjuvant efficacy and safety is a key prerequisite for adjuvant use in vaccination. Therefore, rigorous pre-clinical and clinical research into adjuvant development is essential. Overall, the incorporation of adjuvants allows for greater opportunities in advancing vaccine development and the importance of immune stimulants drives the emergence of novel and more effective adjuvants. This article highlights recent advances in vaccine adjuvant development and provides detailed data from pre-clinical and clinical studies specific to infectious diseases. Future perspectives into vaccine adjuvant development are also highlighted.

Impact of prepartum administration of a vaccine against infectious calf diarrhea on nonspecific colostral immunoglobulin concentrations of dairy cows

Passive transfer of colostral immunoglobulins from the cow to the calf is essential for calf health. The objective of this study was to determine if prepartum administration of a vaccine stimulates increased concentrations of colostral immunoglobulins of dairy cows beyond what is explained by vaccine-specific immunoglobulins. A prospective cohort study was conducted on a spring-calving commercial dairy farm that had a policy of only vaccinating cows with even ear tag numbers with a calf diarrhea vaccine, while cows with odd ear tag numbers were left unvaccinated. Cows in the vaccinated group (even ear tag numbers, n=204) received a sensitizer and booster vaccination with a vaccine against bovine rotavirus (serotypes G6 and G10), bovine coronavirus and E. coli having the K99 pili adherence factor. A sensitizer was given because the study vaccine was different to the vaccine previously used. Cows in the control group (odd ear tag numbers, n=194) received a 2 mL subcutaneous sterile saline solution. Both groups received two treatments at a three-week interval, completing the treatments approximately two weeks prior to the planned start of calving. During the calving period, technicians separated calves from cows immediately after parturition and prior to suckling, and cows were completely milked out within six hours of parturition. Vaccine-specific, total, and nonvaccine-specific (total minus vaccine-specific) concentrations of immunoglobulin classes A, G1, G2a and M (IgA, IgG1, IgG2a and IgM respectively) were quantified by mass spectrometry for 20 colostrum samples from each treatment group. Predicted mean non-vaccine-specific colostral IgM concentrations were 8.76 (95% CI =7.18-10.67) and 5.78 (95% CI =4.74-7.05) mg/ml for vaccinated and control cows respectively (p =0.005). Predicted mean non-vaccine-specific colostral IgG1 concentrations were 106.08 (95% CI =92.07-120.08) and 95.30 (95% CI =81.30-109.31) mg/ml among vaccinated and control cows respectively, however these means were not significantly different (p=0.278). It is thus possible that the vaccine, in addition to specifically managing infectious calf diarrhea, may also have non-specific benefits by improving colostrum quality through increased non-vaccine-specific colostrum IgM concentrations. Further research is necessary to determine the mechanism for these preliminary findings, whether the effect may occur in other immunoglobulin classes, and what impacts it may have on calf health outcomes.

Saponins Form Nonionic Lipid Nanodiscs for Protein Structural Studies by Nuclear Magnetic Resonance Spectroscopy

Structural studies of membrane proteins in native-like environments require the development of diverse membrane mimetics. Currently there is a need for nanodiscs formed with nonionic belt molecules to avoid nonphysiological electrostatic interactions between the membrane system and protein of interest. Here, we describe the formation of lipid nanodiscs from the phospholipid DMPC and a class of nonionic glycoside natural products called saponins. The morphology, surface characteristics, and magnetic alignment properties of the saponin nanodiscs were characterized by light scattering and solid-state NMR experiments. We determined that preparing nanodiscs with high saponin/lipid ratios reduced their size, diminished their ability to spontaneously align in a magnetic field, and favored insertion of individual saponin molecules in the lipid bilayer surface. Further, purification of saponin nanodiscs allowed flipping of the orientation of aligned nanodiscs by 90°. Finally, we found that aligned saponin nanodiscs provide a sufficient alignment medium to allow the measurement of residual dipolar couplings (RDCs) in aqueous cytochrome c.

Cellular Immune Response after Vaccination in Patients with Cancer-Review on Past and Present Experiences

Patients with cancer are at particular risk for infection but also have diminished vaccine responses, usually quantified by the level of specific antibodies. Nonetheless, vaccines are specifically recommended in this vulnerable patient group. Here, we discuss the cellular part of the vaccine response in patients with cancer. We summarize the experience with vaccines prior to and during the SARS-CoV-2 pandemic in different subgroups, and we discuss why, especially in patients with cancer, T cells may be the more reliable correlate of protection. Finally, we provide a brief outlook on options to improve the cellular response to vaccines.

From Bench to the Clinic: The Path to Translation of Nanotechnology-Enabled mRNA SARS-CoV-2 Vaccines

During the last decades, the use of nanotechnology in medicine has effectively been translated to the design of drug delivery systems, nanostructured tissues, diagnostic platforms, and novel nanomaterials against several human diseases and infectious pathogens. Nanotechnology-enabled vaccines have been positioned as solutions to mitigate the pandemic outbreak caused by the novel pathogen severe acute respiratory syndrome coronavirus 2. To fast-track the development of vaccines, unprecedented industrial and academic collaborations emerged around the world, resulting in the clinical translation of effective vaccines in less than one year. In this article, we provide an overview of the path to translation from the bench to the clinic of nanotechnology-enabled messenger ribonucleic acid vaccines and examine in detail the types of delivery systems used, their mechanisms of action, obtained results during each phase of their clinical development and their regulatory approval process. We also analyze how nanotechnology is impacting global health and economy during the COVID-19 pandemic and beyond.

Micro-Aid Liquid 10 Promotes Growth Performance and Health Status of White Shrimp, Litopenaeus vannamei

An experiment was conducted to evaluate the effects of the Micro-Aid Liquid 10 (MAL10) (DPI Global, Porterville, CA, USA), a product made from yucca extract, on growth performance, gut microbiota, and resistance of white shrimp, Litopenaeus vannamei against infectious disease caused by Vibrio alginolyticus. MAL10 was added to shrimp rearing water at different levels of 0 (control), 0.25 mL m3−1 (W0.25), 0.5 mL m3−1 (W0.5), 1 mL m3−1 (W1), and 5 mL m3−1 (W5), respectively, once per week for 70 days. Growth performances, including final body weight, specific growth rate, average daily growth and percentage of weight gain, were significantly improved by adding the MAL10 at levels up to 5 mL m3−1, which may be due to the proliferation of B cells in hepatopancreas of MAL10-treated shrimp. No significant differences in the total viable count and Vibrio-like count in the gut of shrimp were recorded by spread plate method. In the challenge test, shrimp reared in the water supplemented with MAL10 at levels of 1–5 mL m3−1 had significantly lower cumulative mortality after a challenge test with V. alginolyticus compared to shrimp reared in the control, W0.25 and W0.5 groups. Next-generation sequencing indicated that the relative distribution of phylum Proteobacteria in control (80.4%) was higher than the W (77.4%). The proportion of Vibrio was primarily dominant genera in the shrimp intestine and highest in the control group compared to the W group, followed by Spongiimonas, Motilimonas, Demequina, and Shewanella genera. Although there was no statistically significant difference, higher α-diversity indices were recorded in the W5-treated group than in the control group. Therefore, it is considered that MAL10 could be used as a natural alternative in shrimp aquaculture to reduce the risk of infectious disease caused by pathogenic Vibrio and improve the growth performance of white shrimp.

Bio-mimic particles for the enhanced vaccinations: Lessons learnt from the natural traits and pathogenic invasion

In the combat against pathogens, the immune systems were evolved with the immune recognitions against the various danger signals, which responded vigorously upon the pathogen invasions and elicited potent antibodies or T cell engagement against the re-infections. Envisage with the prevailing pandemics and increasing demands for cancer vaccines, bio-mimic particles were developed to imitate the natural traits of the pathogens, which conferred the optimal strategies to stimulate the immune engagement and let to the increased vaccine efficacy. Here, the recent development in bio-mimic particles, as well as the natural cues from the pathogens were discussed. As such, the designing principles that adapted from the physiochemical properties of the pathogens were unfolded as the surface characteristics (hydrophobic, nano-pattern, antigen display, charge), properties (size, shape, softness) and the delivered components (peptide, protein, nuclear acids, toll-like receptor (TLR) agonist, antibody). Additionally, the strategies for the efficient delivery, regarding the biodistribution, internalization and presentation of the antigens were also illustrated. Through reviewing the state-of-art in biomimetic particles, the lesson learnt from the natural traits and pathogenic invasion may shed light on the rational design for the enhanced vaccinations.

Current Status for Controlling the Overlooked Caprine Fasciolosis

The disease fasciolosis is caused by the liver flukes Fasciola hepatica and F. gigantica, which infect a wide range of mammals and production livestock, including goats. These flatworm parasites are globally distributed and predicted to cost the livestock industry a now conservative USD 3 billion per year in treatment and lowered on-farm productivity. Infection poses a risk to animal welfare and results in lowered fertility rates and reduced production yields of meat, milk and wool. This zoonotic disease is estimated to infect over 600 million animals and up to 2.4 million humans. Current and future control is threatened with the global emergence of flukes resistant to anthelmintics. Drug resistance calls for immediate on-farm parasite management to ensure treatments are effective and re-infection rates are kept low, while a sustainable long-term control method, such as a vaccine, is being developed. Despite the recent expansion of the goat industry, particularly in developing countries, there are limited studies on goat-focused vaccine control studies and the effectiveness of drug treatments. There is a requirement to collate caprine-specific fasciolosis knowledge. This review will present the current status of liver fluke caprine infections and potential control methods for application in goat farming.

The Current Status and Challenges in the Development of Vaccines and Drugs against Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2)

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection causes coronavirus disease-19 (COVID-19), which is characterized by clinical manifestations such as pneumonia, lymphopenia, severe acute respiratory distress, and cytokine storm. S glycoprotein of SARS-CoV-2 binds to angiotensin-converting enzyme II (ACE-II) to enter into the lungs through membrane proteases consequently inflicting the extensive viral load through rapid replication mechanisms. Despite several research efforts, challenges in COVID-19 management still persist at various levels that include (a) availability of a low cost and rapid self-screening test, (b) lack of an effective vaccine which works against multiple variants of SARS-CoV-2, and (c) lack of a potent drug that can reduce the complications of COVID-19. The development of vaccines against SARS-CoV-2 is a complicated process due to the emergence of mutant variants with greater virulence and their ability to invoke intricate lung pathophysiology. Moreover, the lack of a thorough understanding about the virus transmission mechanisms and complete pathogenesis of SARS-CoV-2 is making it hard for medical scientists to develop a better strategy to prevent the spread of the virus and design a clinically viable vaccine to protect individuals from being infected. A recent report has tested the hypothesis of T cell immunity and found effective when compared to the antibody response in agammaglobulinemic patients. Understanding SARS-CoV-2-induced changes such as "Th-2 immunopathological variations, mononuclear cell & eosinophil infiltration of the lung and antibody-dependent enhancement (ADE)" in COVID-19 patients provides key insights to develop potential therapeutic interventions for immediate clinical management. Therefore, in this review, we have described the details of rapid detection methods of SARS-CoV-2 using molecular and serological tests and addressed different therapeutic modalities used for the treatment of COVID-19 patients. In addition, the current challenges against the development of vaccines for SARS-CoV-2 are also briefly described in this article.

Systemic and Oral Immunogenicity of Porcine Epidemic Diarrhea Virus Antigen Fused to Poly-Fc of Immunoglobulin G and Expressed in ΔXT/FT Nicotiana benthamiana Plants

Porcine epidemic diarrhea virus (PEDV), a member of the Coronaviridae family has become increasingly probelmatic in the pig farming industry. Currently, there are no effective, globally applicable vaccines against PEDV. Here, we tested a recombinant PEDV vaccine candidate based on the expression of the core neutralising epitope (COE) of PEDV conjugated to polymeric immunoglobulin G scaffold (PIGS) in glycoengineered Nicotiana benthamiana plants. The biological activity of COE-PIGS was demonstrated by binding to C1q component of the complement system, as well as the surface of antigen-presenting cells (APCs) in vitro. The recombinant COE-PIGS induced humoral and cellular immune responses specific for PEDV after both systemic and mucosal vaccination. Altogether, the data indicated that PEDV antigen fusion to poly-Fc could be a promising vaccine platform against respiratory PEDV infection.

Potential Application of Plant-Based Functional Foods in the Development of Immune Boosters

Immune dysfunction, which is responsible for the development of human diseases including cancer, is caused by a variety of factors. Therefore, regulation of the factors influencing the immune response is a potentially effective strategy to counter diseases. Presently, several immune adjuvants are used in clinical practice to enhance the immune response and host defense ability; however, synthetic drugs can exert negative side effects. Thus, the search for natural products of plant origin as new leads for the development of potent and safe immune boosters is gaining considerable research interest. Plant-based functional foods have been shown to exert several immunomodulatory effects in humans; therefore, the application of new agents to enhance immunological and specific host defenses is a promising approach. In this comprehensive review, we have provided an up-to-date report on the use as well as the known and potential mechanisms of bioactive compounds obtained from plant-based functional foods as natural immune boosters. Plant-based bioactive compounds promote immunity through multiple mechanisms, including influencing the immune organs, cellular immunity, humoral immunity, nonspecific immunity, and immune-related signal transduction pathways. Enhancement of the immune response in a natural manner represents an excellent prospect for disease prevention and treatment and is worthy of further research and development using approaches of modern science and technology.

Adjuvant effect of saponin in an oil-based monovalent (serotype O) foot-and-mouth disease virus vaccine on the antibody response in guinea pigs and cattle

To enhance the potency of a foot-and-mouth disease (FMD) vaccine, saponin was included in the vaccine formula. In this study, the combined effect of Montanide ISA 50 and saponin was evaluated. Two experiments were performed in guinea pigs and one in cattle to determine the optimal antigen and saponin doses. Only serotype O of foot-and-mouth disease virus (O/PanAsia-2 of ME-SA topotype) was employed in preparation of the monovalent vaccine. All animals were immunized twice with a four-week interval, except for the negative controls. Blood was collected 10 days after the second booster, and the immune response was evaluated using a serum neutralization test. Oil-based FMD vaccines containing saponin induced higher neutralizing antibody levels than formulations lacking saponin. The addition of saponin to formulations with low antigen payload (2.5 µg of inactivated whole virus particles [146S particles] per dose) gave significantly higher neutralizing antibody levels (p < 0.005) than 5 µg of 146S without saponin, suggesting that it can be used to improve FMD vaccine potency in susceptible animals. No adverse effects were observed in vaccinated cattle or guinea pigs.

Assessment and comparison of phytochemicals and antioxidant properties from various parts of the Australian maroon bush (Scaevola spinescens)

Scaevola spinescens is endemic to Australia and traditionally used as a medicinal plant. While its bioactive compounds have been studied, their concentrations in different parts of the plant have not been reported. This study compared total phenolic content (TPC), flavonoids, saponins and antioxidant properties, as well as major individual phytochemical compounds in the whole root, root bark, root wood, whole stem, stem bark, stem wood, and leaf of S. spinescens. The results showed the leaf had significantly highest concentrations of TPC followed by the root bark and stem bark (47.34, 12.24 and 10.20 mg GAE/g, respectively). Flavonoids concentrations were also significantly higher in the leaf compared to the root bark and stem bark (20.95, 6.22 and 4.19 mg CE/g, respectively). For saponins, the root bark contained significantly highest concentrations (112.58 mg EE/g). Luteolin 7-glucoside was isolated and identified in the leaf of S. spinescens. Eight major compounds were identified with the leaf displaying the highest diversity of major compounds, and in higher concentrations, compared to the other plant constituents. As the leaf and root bark contained the highest concentrations of phytochemicals, these plant parts are recommended as starting material for future studies, to further isolate and identify the major compounds from S. spinescens and investigate their biological properties for use in pharmaceutical and food applications.

Adjuvant-mediated enhancement of the immune response to HIV vaccines

Protection from human immunodeficiency virus (HIV) acquisition will likely require an effective vaccine that elicits antibodies against the HIV-1 envelope glycoproteins (Envs), which are the sole target of neutralizing antibodies and a main focus of vaccine development. Adjuvants have been widely used to augment the magnitude and longevity of the adaptive immune responses to immunizations with HIV-1 Envs and to guide the development of specific immune responses. Here, we review the adjuvants that have been used in combination with HIV-1 Envs in several preclinical and human clinical trials in recent years. We summarize the interactions between the HIV-1 Envs and adjuvants, and highlight the routes of vaccine administration for various formulations. We then discuss the use of combinations of different adjuvants, the potential effect of adjuvants on the elicitation of antibodies enriched in somatic hypermutation and containing long complementarity-determining region 3 of the antibody heavy chain, and the elicitation of non-neutralizing antibodies.

SARS-CoV-2 vaccines strategies: a comprehensive review of phase 3 candidates

The new SARS-CoV-2 virus is an RNA virus that belongs to the Coronaviridae family and causes COVID-19 disease. The newly sequenced virus appears to originate in China and rapidly spread throughout the world, becoming a pandemic that, until January 5th, 2021, has caused more than 1,866,000 deaths. Hence, laboratories worldwide are developing an effective vaccine against this disease, which will be essential to reduce morbidity and mortality. Currently, there more than 64 vaccine candidates, most of them aiming to induce neutralizing antibodies against the spike protein (S). These antibodies will prevent uptake through the human ACE-2 receptor, thereby limiting viral entrance. Different vaccine platforms are being used for vaccine development, each one presenting several advantages and disadvantages. Thus far, thirteen vaccine candidates are being tested in Phase 3 clinical trials; therefore, it is closer to receiving approval or authorization for large-scale immunizations.

Localized and Systemic Immune Responses against SARS-CoV-2 Following Mucosal Immunization

The rapid transmission of SARS-CoV-2 in the USA and worldwide necessitates the development of multiple vaccines to combat the COVID-19 global pandemic. Previously, we showed that a particulate adjuvant system, quil-A-loaded chitosan (QAC) nanoparticles, can elicit robust immunity combined with plasmid vaccines when used against avian coronavirus. Here, we report on the immune responses elicited by mucosal homologous plasmid and a heterologous immunization strategy using a plasmid vaccine and a Modified Vaccinia Ankara (MVA) expressing SARS-CoV-2 spike (S) and nucleocapsid (N) antigens. Only the heterologous intranasal immunization strategy elicited neutralizing antibodies against SARS-CoV-2 in serum and bronchoalveolar lavage of mice, suggesting a protective vaccine. The same prime/boost strategy led to the induction of type 1 and type 17 T-cell responses and polyfunctional T-cells expressing multiple type 1 cytokines (e.g., IFN-γ, TNFα, IL-2) in the lungs and spleens of vaccinated mice. In contrast, the plasmid homologous vaccine strategy led to the induction of local mono and polyfunctional T-cells secreting IFN-γ. Outcomes of this study support the potential of QAC-nano vaccines to elicit significant mucosal immune responses against respiratory coronaviruses.

rOmpF and OMVs as efficient subunit vaccines against Salmonella enterica serovar Enteritidis infections in poultry farms

Salmonella enterica serovar Enteritidis remains the most prevalent serotype causing human salmonellosis through the consumption of contaminated foods, especially poultry products. The development of a subunit vaccine against S. Enteritidis can not only protect chickens against Salmonella infection in the poultry industry but also cut the transmission sources. In this study, both the expressed recombinant outer membrane protein F (rOmpF) and extracted outer membrane vesicles (OMVs) were developed as subunit vaccines against S. Enteritidis challenge in chickens. Immunization with the subunit vaccine could induce not only antibody production but also strong cell-mediated immune response. Both rOmpF plus QuilA adjuvant and OMVs alone had highly protective efficacy against S. Enteritidis challenge and rapidly decreased the colonization of bacteria in chicken. These findings revealed the potential application of rOmpF and OMVs as subunit vaccines in the poultry industry.

Immunoadjuvants for cancer immunotherapy: A review of recent developments

Cancer immunotherapy evolved as a new treatment modality to eradicate tumor cells and has gained in popularity after its successful clinical transition. By activating antigen-presenting cells (APCs), and thus, inducing innate or adaptive immune responses, immunoadjuvants have become promising tools for cancer immunotherapy. Different types of immunoadjuvants such as toll-like receptor (TLR) agonists, exosomes, and metallic and plant-derived immunoadjuvants have been studied for their immunological effects. However, the clinical use of immunoadjuvants is limited by short response rates and various side-effects. The rapid progress made in the development of nanoparticle systems as immunoadjuvant carrier vehicles has provided potential carriers for cancer immunotherapy. In this review article, we describe different types of immunoadjuvants, their limitations, modes of action, and the reasons for their clinical adoption. In addition, we review recent progress made in the nanoparticle-based immunoadjuvant field and on the combined use of nanoparticle-based immunoadjuvants and chemotherapy, phototherapy, radiation therapy, and immune checkpoint inhibitor-based therapy. STATEMENT OF SIGNIFICANCE: Cancer immunotherapy emerged as a new hope for treating malignant tumors. Different types of immunoadjuvants serve as an important tool for cancer immunotherapy by activating an innate or adaptive immune response. Limitation of free immunoadjuvant has paved the path for the development of nanoparticle-based immunoadjuvant therapy with the hope of prolonging the therapeutic efficacy. This review highlights the recent advancement made in nanoparticle-based immunoadjuvant therapy in modulating the adaptive and innate immune system. The application of the combinatorial approach of chemotherapy, phototherapy, radiation therapy adds synergy in nanoparticle-based immunoadjuvant therapy. It will broaden the reader's understanding on the recent progress made in immunotherapy with the aid of immunoadjuvant-based nanosystem.

A Novel Mucosal Adjuvant System for Immunization against Avian Coronavirus Causing Infectious Bronchitis

Infectious bronchitis (IB) caused by infectious bronchitis virus (IBV) is currently a major threat to chicken health, with multiple outbreaks being reported in the United States over the past decade. Modified live virus (MLV) vaccines used in the field can persist and provide the genetic material needed for recombination and emergence of novel IBV serotypes. Inactivated and subunit vaccines overcome some of the limitations of MLV with no risk of virulence reversion and emergence of new virulent serotypes. However, these vaccines are weakly immunogenic and poorly protective. There is an urgent need to develop more effective vaccines that can elicit a robust, long-lasting immune response. In this study, we evaluate a novel adjuvant system developed from Quil-A and chitosan (QAC) for the intranasal delivery of nucleic acid immunogens to improve protective efficacy. The QAC adjuvant system forms nanocarriers (<100 nm) that efficiently encapsulate nucleic acid cargo, exhibit sustained release of payload, and can stably transfect cells. Encapsulation of plasmid DNA vaccine expressing IBV nucleocapsid (N) protein by the QAC adjuvant system (pQAC-N) enhanced immunogenicity, as evidenced by robust induction of adaptive humoral and cellular immune responses postvaccination and postchallenge. Birds immunized with pQAC-N showed reduced clinical severity and viral shedding postchallenge on par with protection observed with current commercial vaccines without the associated safety concerns. Presented results indicate that the QAC adjuvant system can offer a safer alternative to the use of live vaccines against avian and other emerging coronaviruses.IMPORTANCE According to 2017 U.S. agriculture statistics, the combined value of production and sales from broilers, eggs, turkeys, and chicks was $42.8 billion. Of this number, broiler sales comprised 67% of the industry value, with the production of >50 billion pounds of chicken meat. The economic success of the poultry industry in the United States hinges on the extensive use of vaccines to control infectious bronchitis virus (IBV) and other poultry pathogens. The majority of vaccines currently licensed for poultry health include both modified live vaccine and inactivated pathogens. Despite their proven efficacy, modified live vaccine constructs take time to produce and could revert to virulence, which limits their safety. The significance of our research stems from the development of a safer and potent alternative mucosal vaccine to replace live vaccines against IBV and other emerging coronaviruses.

A Leishmania amastigote-specific hypothetical protein evaluated as recombinant protein plus Th1 adjuvant or DNA plasmid-based vaccine to protect against visceral leishmaniasis

Most studies evaluating vaccine candidates against visceral leishmaniasis (VL) have used parasite promastigote-expressed antigens; however, Leishmania proteins expressed in the amastigote forms should be considered, since few hours after infection this stage comes into contact with the host immune system and is responsible for the development of the disease. In this context, in the present study, a Leishmania amastigote-specific hypothetical protein, called LiHyJ, was evaluated as a recombinant protein plus saponin as an adjuvant or DNA vaccine to protect against VL. The vaccine effect was evaluated by means of the evaluation of immunological and parasitological analyses performed in BALB/c mice against Leishmania infantum infection. Results showed that rLiHyJ/saponin and DNA LiHyJ induced significantly higher levels of anti-protein and anti-parasite IFN-γ, IL-12, GM-CSF, and IgG2a isotype antibodies, which were associated with a low presence of IL-4 and IL-10. DNA vaccination induced higher IFN-γ production, mainly by CD8⁺ T cells, while rLiHyJ/saponin stimulated the production of this cytokine, mainly by CD4⁺ T cells. The parasite load evaluated in distinct organs showed that both immunization schedules significantly reduced organic parasitism, when compared to the controls. Similar results were found in the immunological and parasitological assays when using the recombinant protein or DNA, although the vaccination with rLiHyJ plus saponin induced a slightly higher Th1 response and lower parasite load, when compared to the use of DNA plasmid. The protein also proved to be immunogenic when peripheral blood mononuclear cells of treated VL patients and healthy subjects were in vitro stimulated, since higher IFN-γ and lower IL-4 and IL-10 levels were found in the culture supernatants. In conclusion, LiHyJ should be considered in future studies as a vaccine candidate to protect against VL.

Preparation and efficacy of freeze-dried inactivated vaccine against bovine viral diarrhea virus genotypes 1 and 2, bovine herpes virus type 1.1, bovine parainfluenza-3 virus, and bovine respiratory syncytial virus

Purpose

Bovine respiratory disease is a worldwide health concern in the feedlot cattle causing morbidity and mortality in young with major economic losses to the producer. Programs of vaccination are integral parts of preventive health programs. We aim to prepare and evaluate lyophilized combined inactivated viruses (bovine viral diarrhea virus [BVDV] genotypes 1 and 2, bovine herpes virus type 1.1 [BoHV-1.1], bovine parainfluenza-3 virus [BPI-3V], and bovine respiratory syncytial virus [BRSV]) vaccine using saponin as a solvent and adjuvant in cattle.

Materials and Methods

Lyophilized Pneumo-5 vaccine was formulated to include the inactivated BVDV genotypes 1 and 2, BoHV-1.1, BPI-3V, and BRSV. The saponin solution was used as an adjuvant and solvent. The prepared vaccines were adjusted to contain 1- and 1.5-mg saponin/dose. It was evaluated for its sterility, safety, and potency in mice and calves. The antibody titers in vaccinated calves were measured by virus neutralization test and enzyme-linked immunosorbent assay (ELISA).

Results

The Pneumo-5 vaccine was found to be free from any contaminants and safe in mice. Meanwhile, the vaccine showed safety in calves which inoculated intramuscularly with the double dose of the vaccines. The overall immune response reached its peak in the 2nd-month post-vaccination. The vaccine contained saponin 1.5 mg/dose reached its antibodies peak in the 4th-week post-vaccination. All groups of vaccinated calves with both concentrations of the saponin did not show statistical significance in antibody titers measured by serum neutralization test and/or ELISA.

Conclusion

The prepared vaccine, namely Pneumo-5, and adjuvanted with either 1 or 1.5 mg/dose saponin was proved safe and potent for effectual protection of calves against BVDV genotypes 1 and 2, BoHV-1.1, BPI-3V, and BRSV.

Evaluation of the protective efficacy of a Leishmania protein associated with distinct adjuvants against visceral leishmaniasis and in vitro immunogenicity in human cells

The treatment against visceral leishmaniasis (VL) presents problems, mainly related to the toxicity and/or high cost of the drugs. In this context, a prophylactic vaccination is urgently required. In the present study, a Leishmania protein called LiHyE, which was suggested recently as an antigenic marker for canine and human VL, was evaluated regarding its immunogenicity and protective efficacy in BALB/c mice against Leishmania infantum infection. In addition, the protein was used to stimulate peripheral blood mononuclear cells (PBMCs) from VL patients before and after treatment, as well as from healthy subjects. Vaccination results showed that the recombinant (rLiHyE) protein associated with liposome or saponin induced effective protection in the mice, since significant reductions in the parasite load in spleen, liver, draining lymph nodes, and bone marrow were found. The parasitological protection was associated with Th1-type cell response, since high IFN-γ, IL-12, and GM-CSF levels, in addition to low IL-4 and IL-10 production, were found. Liposome induced a better parasitological and immunological protection than did saponin. Experiments using PBMCs showed rLiHyE-stimulated lymphoproliferation in treated patients' and healthy subjects' cells, as well as high IFN-γ levels in the cell supernatant. In conclusion, rLiHyE could be considered for future studies as a vaccine candidate against VL.

Liposomal Formulation of ChimeraT, a Multiple T-Cell Epitope-Containing Recombinant Protein, Is a Candidate Vaccine for Human Visceral Leishmaniasis

Background: Leishmaniases are neglected diseases caused by infection with Leishmania parasites and there are no human vaccines in use routinely. The purpose of this study was to examine the immunogenicity of ChimeraT, a novel synthetic recombinant vaccine against visceral leishmaniasis (VL), incorporated into a human-compatible liposome formulation. Methods: BALB/c mice were immunized subcutaneously with ChimeraT/liposome vaccine, ChimeraT/saponin adjuvant, or ChimeraT/saline and immune responses examined in vitro and in vivo. Results: Immunization with the ChimeraT/liposome formulation induced a polarized Th1-type response and significant protection against L. infantum infection. ChimeraT/liposome vaccine stimulated significantly high levels of interferon (IFN)-γ, interleukin (IL)-12, and granulocyte macrophage-colony stimulating factor (GM-CSF) cytokines by both CD4 and CD8 T-cells, with correspondingly lower levels of IL-4 and IL-10 cytokines. Induced antibodies were predominantly IgG2a isotype, and homologous antigen-stimulated spleen cells produced significant nitrite as a proxy for nitric oxide (NO). Furthermore, we examined a small number of treated VL patients and found higher levels of circulating anti-ChimeraT protein IgG2 antibodies, compared to IgG1 levels. Conclusions: Overall, the liposomal formulation of ChimeraT induced a protective Th1-type immune response and thus could be considered in future studies as a vaccine candidate against human VL.

A liquid chromatography coupled to quadrupole-time-of-flight-mass spectrometry (LC-QTOF-MS) method for identification analysis of saponins from Quillaja saponaria bark extracts in foot-and-mouth disease vaccines: Development, validation and applicability

Saponins from Quillaja saponaria have been commonly used as immunomodulatory adjuvants in foot-and-mouth disease vaccines (FMDVs). However, due to the lack of consensus over the possible exacerbation of local inflammatory responses in cattle and its economic impacts, their use has been discouraged by Brazilian authorities. A qualitative method intended to determine the presence of saponins from Q. saponaria bark extracts in FMDVs was developed and validated. Instrumental analysis was performed using an liquid chromatography (LC) coupled to a quadrupole-time-of-flight-mass spectrometry (TOF-MS) system. The method was validated according to the International Conference on Harmonization Harmonized Tripartite Guideline Q2 (R1) and Brazilian Ministry of Agriculture, Livestock and Food Supply Analytical Quality Assurance Guidelines. Validation parameters were determined and considered suitable to the established criteria. The validated method has been applied in routine analysis in the National Agricultural Laboratory at Rio Grande do Sul (LANAGRO-RS). All results obtained were in agreement with the vaccine's composition described by the manufacturer. The method is easy and adequate for analysis in routine laboratories. To the best of the authors' knowledge, this is the first report of a method which intends to investigate the presence of saponins from Q. saponaria bark extracts in veterinary vaccines.

Enhancement in humoral response against inactivated Newcastle disease vaccine in broiler chickens administered orally with plant-derived soyasaponin

The present study aimed to evaluate the immunopotentiating effect of plant-derived soyasaponin and its immunogenicity in chickens challenged with Newcastle disease virus (NDV). Soyasaponin was extracted from soybean seeds and detected using the phytochemical tests, followed by quantification through the dry-weight method. One-day-old broiler chicks (n = 90) were divided into 3 groups, named as A, B, and C. Group A birds were orally administrated with soyasaponin (5 mg/kg), followed by immunization with inactivated ND vaccine intramuscularly (IM), whereas group B birds were vaccinated with inactivated ND vaccine alone. Group C birds were kept unvaccinated. A booster dose on day 21 was also administered IM to group A and B birds. At day 35, all 3 groups were challenged with NDV. To determine the immunogenicity potential of soyasaponin, antibody titer was measured using the hemagglutination inhibition test before and after the NDV challenge. Histochemical examination was performed to determine the pathological changes associated with NDV infection. Foam formation and hemolytic activity confirmed the presence of saponin in soya bean extract. Group A birds showed a higher antibody response compared with group B and C birds. The disease challenge study showed that soyasaponin-adjuvanted NDV vaccine provided complete protection to group A birds against ND. Moreover, no side effects of soyasaponin were observed on the growth performance of birds during the experiment. Therefore, we can conclude that soyasaponin is a potential immunogenic agent and therefore could be a promising candidate to launch a protective humoral response against ND in chickens.

Boosting Tat DNA vaccine with Tat protein stimulates strong cellular and humoral immune responses in mice

The aim of the present study was to evaluate the efficacy of a novel DNA priming-protein boosting regimen in simultaneous enhancing humoral and cellular immunogenicity of the HIV-1-Tat-based candidate vaccines in mice. The experimental BALB/c mice were successfully immunized with the HIV-1-Tat DNA vaccine and boosted with the corresponding protein vaccine over a two-week interval and the elicitation of cellular and humoral immune responses were simultaneously assessed. The results showed that the prime-boost immunization has significantly given rise to lymphocyte proliferation and CTL responses, as well as the levels of both IgG and IgG antibodies compared to the other candidate vaccines. The results of the Th polarization also revealed that the Th1: Th2 indexes in the mice vaccinated with the HIV-1 Tat protein, Tat DNA, and the prime-boost vaccines were 1.03, 1.19, and 1.25, respectively. The results suggest that co-administration of the HIV-1-Tat DNA with the corresponding protein may serve as a potential formulation for enhancing of Tat vaccineinduced immunity and has measurable effects on shaping vaccines' induced Th polarization.

Intestinal changes and performance parameters in ticks feeding on calves immunized with subunits of immunogens against Rhipicephalus microplus

We describe the intestinal changes and biological parameters of the tick species Rhipicephalus microplus exposed to the immune response of calves vaccinated with two subunits of immunogens. The first group of Bos taurus calves was immunized with a synthetic peptide (SBm7462), whereas the second group received an inoculum for synthetic control. The third group was immunized with a recombinant peptide (rSBm7462); an inoculum was injected into a fourth group of calves for recombinant control. Each formulation was administered to these calves during three times at intervals of 30 days. At 21 days after the last immunization, the calves were challenged using a total of 4500 larvae per animal. Indirect ELISA was realized to identify the kinetics of IgGs from samples of calves studied. Naturally detaching ticks were collected for analyses of biological performance and histological changes in the midgut. We dissected randomly detached ticks. The midgut of each of these ticks was removed and processed routinely for histology, stained with hematoxylin-eosin (H&E) and slow Giemsa. Slides were also subjected to immunohistochemistry. The antibody response showed significant induction of high-affinity IgGs in calves immunized with both peptides in comparison to calves of the control groups. Histological changes included damage of the intestinal epithelium in ticks fed on immunized hosts and intense immunostaining in midgut cells, using the serum of calves immunized with recombinant peptide. There were significant differences in all biological performing parameters of ticks detached from vaccinated calves in comparison with ticks of the control groups. We identified reductions of 87.7 and 93.5% in engorged ticks detached from calves immunized with a synthetic and recombinant peptides, respectively, a 28 and 8.60% lower egg mass in groups immunized with synthetic and recombinant peptides, respectively, and a 38.4% reduction of the value of nutrient index/tick in the group immunized with the recombinant peptide. Our findings show that the immune response induced by small peptides in cattle can modify the digestion and metabolism of ticks fed on vaccinated animals, resulting in changes in tick performance.

Rapid test to detect cytotoxic activity in vaccines against foot-and-mouth disease

ABSTRACT Substances with cytotoxic activity present in vaccines against the foot-and-mouth disease may interfere with methods used to detect residual live virus in the product or cause undesirable postvaccination reactions. This study describes a rapid in vitro test to detect cytotoxic activity in water-in-oil vaccines against foot-and-mouth disease using a commercial saponin as a cytotoxic agent and a solution of sheep’s red blood cells as substrate. Hemolytic and cytotoxic activity was analyzed using experimental and commercial vaccines prepared with and without saponin. The hemolytic and cytotoxic potential of preparations containing saponin was evident. In contrast, hemolytic and cytotoxic activities were not observed in vaccines without saponin in their composition. The method described here allows to easily detect if the vaccine under study has cytotoxic activity, making it possible to select the most appropriate method to process the sample to be used for the innocuity test. Additionally, due to undesirable effects that may be observed in animals receiving vaccines containing saponin in their formulation, the use of the rapid test described here allows to identify those vaccines with cytotoxic activity and to verify the presence of saponin on them, through the mass spectrometry method.