Vaccine value profile for Klebsiella pneumoniae.

Klebsiella pneumoniae causes community- and healthcare-associated infections in children and adults. Globally in 2019, an estimated 1.27 million (95% Uncertainty Interval [UI]: 0.91-1.71) and 4.95 million (95% UI: 3.62-6.57) deaths were attributed to and associated with bacterial antimicrobial resistance (AMR), respectively. K. pneumoniae was the second leading pathogen in deaths attributed to AMR resistant bacteria. Furthermore, the rise of antimicrobial resistance in both community- and hospital-acquired infections is a concern for neonates and infants who are at high risk for invasive bacterial disease. There is a limited antibiotic pipeline for new antibiotics to treat multidrug resistant infections, and vaccines targeted against K. pneumoniae are considered to be of priority by the World Health Organization. Vaccination of pregnant women against K. pneumoniae could reduce the risk of invasive K.pneumoniae disease in their young offspring. In addition, vulnerable children, adolescents and adult populations at risk of K. pneumoniae disease with underlying diseases such as immunosuppression from underlying hematologic malignancy, chemotherapy, patients undergoing abdominal and/or urinary surgical procedures, or prolonged intensive care management are also potential target groups for a K. pneumoniae vaccine. A 'Vaccine Value Profile' (VVP) for K.pneumoniae, which contemplates vaccination of pregnant women to protect their babies from birth through to at least three months of age and other high-risk populations, provides a high-level, holistic assessment of the available information to inform the potential public health, economic and societal value of a pipeline of K. pneumoniae vaccines and other preventatives and therapeutics. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public-private partnerships, and multi-lateral organizations, and in collaboration with stakeholders from the WHO. All contributors have extensive expertise on various elements of the K.pneumoniae VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information.

Vaccine value profile for Neisseria gonorrhoeae.

Neisseria gonorrhoeae infection (gonorrhoea) is a global public health challenge, causing substantial sexual and reproductive health consequences, such as infertility, pregnancy complications and increased acquisition or transmission of HIV. There is an urgency to controlling gonorrhoea because of increasing antimicrobial resistance to ceftriaxone, the last remaining treatment option, and the potential for gonorrhoea to become untreatable. No licensed gonococcal vaccine is available. Mounting observational evidence suggests that N. meningitidis serogroup B outer membrane vesicle-based vaccines may induce cross-protection against N. gonorrhoeae (estimated 30%-40% effectiveness using the 4CMenB vaccine). Clinical trials to determine the efficacy of the 4CMenB vaccine against N. gonorrhoeae are underway, as are Phase 1/2 studies of a new gonococcal-specific vaccine candidate. Ultimately, a gonococcal vaccine must be accessible, affordable and equitably dispensed, given that those most affected by gonorrhoea are also those who may be most disadvantaged in our societies, and most cases are in less-resourced settings. This vaccine value profile (VVP) provides a high level, holistic assessment of the current data to inform the potential public health, economic and societal value of pipeline vaccines. This was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships and multi-lateral organizations. All contributors have extensive expertise on various elements of the N. gonorrhoeae VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using published data obtained from peer-reviewed journals or reports.

Development of an inactivated whole cell vaccine through immersion for immunoprophylaxis of Francisella orientalis infections in Nile tilapia (Oreochromis niloticus L.) fingerlings and juveniles.

Francisella orientalis infections, known as francisellosis, are one of the most important diseases affecting the production of Nile tilapia, causing high mortality rates in the most susceptible fish stages: fingerlings and juveniles. Antibiotic therapy is the method of choice for treating the disease, as there are no commercially available vaccines. In this study, we developed an inactivated whole-cell vaccine using an isolate of F. orientalis in combination with the aqueous adjuvant Montanide IMS 1312 VG, which was administered to Nile tilapia through immersion. Two immunization trials (1 and 2) were conducted with fish at the fingerling and juvenile stages. For each trial, five different experimental groups were established: a complete vaccine (bacterin in combination with aqueous adjuvant), bacterin, aqueous adjuvant, and positive and negative controls. Thirty days after vaccination, an experimental challenge was performed through intraperitoneal injection of the same F. orientalis isolate. As a result, the vaccinated fingerlings were the only group in which mortality and progression of clinical signs of francisellosis were statistically significantly reduced, although relative percentage of survival (RPS) was low at 50%. In the juvenile group, RPS was higher at 63%, but not statistically significant. Nevertheless, an RPS of only 50% is acceptable for using vaccines in the field. The bacterin and adjuvant treatments alone were not effective, showing an RPS of 37% and 0%, respectively. Post-vaccination mortality was observed in the group exposed only to the adjuvant, which may indicate excessive immune stimulation at this stage. Interestingly, the immune response elicited by the vaccine was unable to eliminate the pathogen from the host; therefore, the surviving animals became carriers. Although the immune response elicited by the vaccine was unable to eliminate the pathogen from the host, this vaccine formulation could be a viable alternative for use in the field and serve as another means of controlling the mortality caused by the pathogen. Our study provides the first report of vaccination, using immersion, against francisellosis at the most susceptible stages of farmed Nile tilapia. Future studies should address the efficiency of immersion vaccines under field conditions.

Oral vaccination of piglets against Mycoplasma hyopneumoniae using silica SBA-15 as an adjuvant effectively reduced consolidation lung lesions at slaughter.

Mycoplasma (M.) hyopneumoniae is the main pathogen of porcine enzootic pneumonia (PEP). Its controlling is challenging, and requires alternative strategies. This study aimed to develop an oral vaccine against M. hyopneumoniae using a nanostructured mesoporous silica (SBA-15) as an adjuvant, and compare its effect with an intramuscular (IM) commercial vaccine (CV). Fifty 24 day-old M. hyopneumoniae-free piglets composed five equal groups for different immunization protocols, consisting of a CV and/or oral immunization (OI). Control piglets did not receive any form of immunization. All piglets were challenged with M. hyopneumoniae strain 232 on D49 by tracheal route. IgA antibody response in the respiratory tract, bacterial shedding and serum IgG were evaluated. The piglets were euthanized on 28 (D77) and 56 (D105) days post-infection. Lung lesions were macroscopically evaluated; lung fragments and bronchoalveolar fluid (BALF) were collected for estimation of bacterial loads by qPCR and/or histopathology examination. All immunization protocols induced reduction on Mycoplasma-like macroscopic lung lesions. IgA Ab responses anti-M. hyopneumoniae, the expression of IL-4 cytokine and a lower expression of IL-8 were induced by CV and OI vaccines, while IgG was induced only by CV. Oral immunization using silica as a carrier-adjuvant can be viable in controlling M. hyopneumoniae infection.

The adjuvanticity of manganese for microbial vaccines via activating the IRF5 signaling pathway.

Manganese (Mn2+) has been reported to activate macrophages and NK cells, and to induce the production of type-I interferons (IFNs) by activating the cGAS-STING pathway. Few studies have been conducted on its adjuvanticity to microbial vaccines, and on the involvement of the interferon regulatory factor (IRF) 5 signaling pathway in the adjuvanticity. In this study, we demonstrated that Mn2+ could facilitate various microbial vaccines to induce enhanced antibody responses, and facilitate the influenza virus vaccine to induce protective immunity against the influenza virus challenge. When formulated in vaccines, Mn2+ could activate murine CD4+ T cells, CD8+ T cells, B cells and DCs, and induce the expression and phosphorylation of TANK-binding kinase 1 (TBK1) and IRF5 in the splenocytes of the immunized mice, resulting in the increased expression of type-I IFNs, TNF-α, B cell-activating factor of the TNF family (BAFF) and B lymphocyte-induced maturation protein-1 (Blimp-1). The induced TBK1 could recruit and bind the IRF5. Furthermore, the Mn2+ induced expression of IRF5 and Blimp-1 was prohibited by a IRF5 interfering oligonucleotide. The data suggest the Mn2+ could be used as a novel type of adjuvants for microbial vaccines, and the activation of IRF5 signaling pathway might involve in the adjuvanticity.

Immunization with recombinant protein Ag43::UpaH with alum and 1,25(OH)2D3 adjuvants significantly protects Balb/C mice against urinary tract infection caused by uropathogenic Escherichia coli.

The majority of urinary tract infections (UTIs) are caused by uropathogenic Escherichia coli (UPEC). Designing a vaccine will certainly reduce the occurrence of infection and antibiotic resistance of the isolates. Antigen 43 (Ag43) and autotransporter H (UpaH) have been associated with the virulence of UPEC. In the present study, the efficacy of different formulations of a hybrid protein composed of Ag43 and UpaH with and without alum and 1,25(OH)2D3 (Vitamin D3) adjuvants were evaluated in mice model. A significant increase in IgG and cellular responses was developed against Ag43::UpaH as compared to the control mice. The addition of alum or a mixture of alum and Vitamin D3 to the protein significantly enhanced the serum IgG responses and tended to remain in a steady state until 6 months. In addition, the mentioned formulations produced significant amounts of IgG1, IL-4, and IL-17 as compared to the fusion protein alone. In addition to the mentioned formulations, the combination of protein with Vitamin D3 also resulted in significantly higher serum IgA and IFN-γ levels as compared to the fusion protein alone. Mice immunized with fusion plus alum and formulation protein admixed with both alum and Vitamin D3 significantly reduced the bacterial load in the bladders and kidneys of mice as compared to the control. In this study, for the first time, the ability of a novel hybrid protein in combination with adjuvants alum and Vitamin D3 was evaluated against UPEC. Our results indicated that fusion Ag43::UpaH admixed with alum and Vitamin D3 could be a promising candidate against UTIs.

In vitro evaluation of novel (nanoparticle) oral delivery systems allow selection of gut immunomodulatory formulations.

Oral delivery is the most convenient way to vaccinate cultured fish, however it is still problematic, primarily due to a lack of a commercially valid vaccine vehicle to protect the antigen against gastric degradation and ensure its uptake from the intestine. With the goal of advancing the potential to vaccinate orally, this study evaluates a novel silicon nanoparticle-based vehicle (VacSaf carrier). Aeromonas salmonicida antigens were formulated with the VacSaf carrier using different preparation methods to generate dry powder and liquid formulations. Twelve formulations were first subjected to an in vitro evaluation where the A. salmonicida bacterin conjugated to VacSaf carriers were found superior at inducing pro-inflammatory cytokine expression in primary leucocyte cultures and the macrophage/monocyte cell line RTS-11 compared with A. salmonicida bacterin alone. This was especially apparent after exposure to acid conditions to mimic stomach processing. One formulation (FD1) was taken forward to oral delivery using two doses and two administration schedules (5 days vs 10 days, the latter 5 days on, 5 days off, 5 days on), and the transcript changes of immune genes in the intestine (pyloric caeca, midgut and hindgut) and spleen were evaluated by qPCR and serum IgM was measured by ELISA. The VacSaf carrier alone was shown to be safe for use in vivo, in that no side-effects were seen, but it did induce expression of some cytokines, and may have value as an oral adjuvant candidate. The FD1 bacterin formulation was effective at inducing a range of cytokines associated with innate and adaptive immunity, mainly in the pyloric caeca, compared to A. salmonicida bacterin alone (which had almost no effect), and confirms the immune competence of this gut region following appropriate oral vaccination. These results reveal that in vitro screening of formulations for oral delivery has value and can be used to assess the most promising formulations to test further.

Early immune response in large yellow croaker (Larimichthys crocea) after immunization with oral vaccine.

Mesoporous silica nanoparticles (MSNs) have been used in the field of biomedicine as antigen carriers and adjuvants for protective antigens. In the present study, an oral nanovaccine against Vibrio alginolyticus was prepared employing MSNs as carriers. The uptake of the dihydrolipoamide dehydrogenase (DLDH) antigens in the intestine of large yellow croaker was evaluated using an immunohistochemistry assay. Additionally, the effects of the nanovaccine on the early immune response in large yellow croaker were investigated via oral vaccination. The presence of the antigens was detected in the mucosa and lamina propria of the foregut, midgut, and hindgut of large yellow croaker at 3 h following oral immunization. The expression levels of cytokines (i.e., lysozyme, IFN-γ, IFITM, TNF-α, IL-1ß, IL-2, IL-4, IL-10, and IL-13) in the intestine, spleen, and head kidney tissues of large yellow croaker before and after the immune challenge were determined via RT-qPCR assay. The obtained results revealed that the expression levels of lysozyme, IFN-γ, IFITM, TNF-α, IL-1ß, IL-2, IL-4, IL-10, and IL-13 in the intestine and head kidney of the vaccinated large yellow croaker, as well as the expression of lysozyme, IL-1ß, and IL-10 in the spleen, exhibited time-dependent oscillation regulation patterns. Notably, the nanovaccine immunization could induce early (6 h) and high expression of IFN-γ in the spleen and kidney tissues after the bacterial infection. The current study supplements the available data on the early immune response to fish nanovaccines. It also provides a valuable theoretical basis for the future development of large yellow croaker oral vaccines.

High efficacy and economical procedure of oral vaccination against Lactococcus garvieae/Streptococcus iniae in rainbow trout (Oncorhynchus mykiss).

The present study was aimed to examine the efficacy of chitosan-alginate coated vaccines against pathogenicity of Lactococcus garvieae and Streptococcus iniae in rainbow trout. Fish were divided into four groups including: Group A: fish immunized by chitosan-alginate coated vaccine, Group B: fish immunized by non-coated vaccine, Group C: fish feed by chitosan-alginate coated pellets without vaccine and Group D: fish feed by basic diet (non-coated and without vaccine). In groups A and B, the vaccination was carried out for 14 days and after that supplemented with fundamental diet (control diet). Comparable to groups A and B, fish of group C were also fed 14 days with test diets and after that fed control food. On day 0, 20, 40 and 60 of the experiment, serum samples were given. Fish have been challenged with live L. garvieae and S. iniae after 60 days. The levels of bactericidal activity and complement activity among innate immunity components extended on day 20 of the research and after that decreased in group A and B (P < 0.05) all through the examination. The relative expression of IL-6 and IgM in groups A and B extended on examination day 20. The expression of these genes illustrated no advancements in different groups in during the examination (P > 0.05). In group A, the serum antibody titer against L. garvieae and S. iniae broadly raised on day 40 and 60 of examination, whereas in group B, the immune response titer against S. iniae and L. garvieae illustrated a significant elevation on day 60 of the trial (P < 0.05). After challenge with live bacteria, survival rate of 83 ± 9.1%(challenged with S. iniae) and 72.18 ± 9.8% (challenged with L. garvieae) were gotten independently in group A, which were higher than survival of other exploratory groups (P < 0.05). In conclusion, the results of the present examination appear that the orally vaccination of rainbow trout with chitosan-alginate covered vaccine stimulates immunity system and also efficiently protects rainbow trout against Lactococcus garvieae and Streptococcus iniae.

A CpG-riched plasmid as vaccine adjuvant reduce antigen dose of an inactivated Vibrio anguillarum vaccine in turbot (Scophthalmus maximus L.).

Inactivated vaccines are often applied with adjuvants in commercial fish farming. Although some mineral or non-mineral oil adjuvants show efficient improvement with inactivated vaccines, but sometimes bring side effects such as tissue adhesion and granulomatous lesion at the injection site. CpG ODN is a novel type of soluble adjuvant which has been proved to possess excellent advantages in fish vaccine development. In this study, we designed a tandem sequence of CpG ODN synthesized in plasmid pcDNA 3.1, and an inactivated Vibrio anguillarum vaccine developed in our previous work was chosen for determining the efficiency of the CpG-riched plasmids (pCpG) as an adjuvant. Results showed that pCpG we designed can offer higher immunoprotection with the vaccine. Interestingly, even below the minimum immune dosage of the vaccine, a high RPS of 84% was observed once the vaccine was administrated with the pCpG. Serum specific antibody titer, superoxide dismutase and total protein were enhanced and some immune genes related to both innate and adaptive immune response were upregulated, implying an effective auxiliary function of the pCpG. Totally, our study suggested that the pCpG is a potential and available adjuvant for turbot vaccine development.

Preparation and immunological characterization of an inactivated canine Clostridium perfringens type A vaccine.

Clostridium perfringens is the main cause of sudden death in dogs and currently there is no vaccine to prevent it. In this study, a canine C. perfringens type A strain was used to prepare a vaccine. C. perfringens was inactivated by formaldehyde and adjuvants were added. The safety and immunological characteristics of the inactivated C. perfringens vaccine were evaluated in mice and dogs. The results showed that the C. perfringens vaccine was safe and had immunoprotective activity. The serum antibody titre of immunized mice reached up to 6·25 × 104 . Both single immunization of 4 ml and dual immunizations of 2 ml each provided good immune protection, with five of five immunized dogs surviving. This study also studied a detoxified crude α-toxin extract vaccine. The results showed that a single immunization with 0·5 ml of the detoxified crude α-toxin extract vaccine provided immune protection, with five of five immunized dogs surviving. The inactivated C. perfringens type A vaccine can be used to prevent canine C. perfringens infections. SIGNIFICANCE AND IMPACT OF THE STUDY: Clostridium perfringens is the main cause of sudden death in dogs and currently there is no vaccine to prevent it. In this study, an inactivated canine C. perfringens vaccine and a detoxified crude α-toxin vaccine were prepared. The safety and protective effects of these vaccines were evaluated using mouse and dog models. The vaccines were shown to be safe and to provide immune protection effects that can be used to prevent canine C. perfringens infection.

Exploratory cohort study to determine if dry cow vaccination with a Salmonella Newport bacterin can protect dairy calves against oral Salmonella challenge.

BACKGROUND: Salmonellosis is a major cause of morbidity and mortality in neonatal calves, often occurring before preventative vaccines can be administered. HYPOTHESIS/OBJECTIVE: To evaluate the protective effect on calves of colostrum from cows vaccinated with a commercially available Salmonella Newport bacterin against a Salmonella Typhimurium challenge. ANIMALS: Twenty Holstein bull calves from a university dairy farm. METHODS: Nonrandomized placebo-controlled trial in which colostrum was harvested from 30 cows that received 2 doses of either Salmonella bacterin or saline before calving. Colostrum collected from each group was pooled and fed to 2 groups of 10 calves at birth. At approximately 2 weeks of age, calves were challenged with Salmonella Typhimurium. Clinical, hematologic, microbiological, and postmortem findings were compared between the 2 groups. RESULTS: No differences in mortality, clinical findings, hematology results, blood and fecal cultures, or necropsy findings between the 2 groups were observed. Vaccinated cows had higher colostral titers, and calves fed this colostrum had higher serum titers (mean difference, 0.429; mean [SE], 0.852 [0.02] for vaccinated versus 0.423 [0.02] for control calves). CONCLUSIONS AND CLINICAL IMPORTANCE: Transfer of colostral immunoglobulins from Salmonella enterica serotype Newport bacterin to neonatal calves was not sufficient to decrease mortality, clinical signs, sepsis, intestinal damage, or fecal shedding when exposed to a highly pathogenic Salmonella isolate. A large-scale randomized controlled clinical trial is needed to evaluate the efficacy of this bacterin when administered in the dry period for prevention of salmonellosis in neonatal calves.

Application of an Endothelial Cell Culture Assay for the Detection of Neutralizing Anti-Clostridium Perfringens Beta-Toxin Antibodies in a Porcine Vaccination Trial.

BACKGROUND: Beta-toxin (CPB) is the major virulence factor of Clostridium perfringens type C, causing hemorrhagic enteritis in newborn pigs but also other animals and humans. Vaccines containing inactivated CPB are known to induce protective antibody titers in sow colostrum and neutralization of the CPB activity is thought to be essential for protective immunity in newborn piglets. However, no method is available to quantify the neutralizing effect of vaccine-induced antibody titers in pigs. (2) Methods: We developed a novel assay for the quantification of neutralizing anti-CPB antibodies. Sera and colostrum of sows immunized with a commercial C. perfringens type A and C vaccine was used to determine neutralizing effects on CPB induced cytotoxicity in endothelial cells. Antibody titers of sows and their piglets were determined and compared to results obtained by an ELISA. (3) Results: Vaccinated sows developed neutralizing antibodies against CPB in serum and colostrum. Multiparous sows developed higher serum and colostrum antibody titers after booster vaccinations than uniparous sows. The antibody titers of sows and those of their piglets correlated highly. Piglets from vaccinated sows were protected against intraperitoneal challenge with C. perfringens type C supernatant. (4) Conclusions: The test based on primary porcine endothelial cells quantifies neutralizing antibody activity in serum and colostrum of vaccinated sows and could be used to reduce and refine animal experimentation during vaccine development.

Efficacy and safety of a non-mineral oil adjuvanted injectable vaccine for the protection of Atlantic salmon (Salmo salar L.) against Flavobacterium psychrophilum.

Flavobacterium psychrophilum is the causative agent of Rainbow Trout Fry Syndrome which has had a major impact on global salmonid aquaculture. Recent outbreaks in Atlantic salmon in Scotland and Chile have added to the need for a vaccine to protect both salmon and trout. At present no licensed vaccines are available in Europe, leaving antibiotics as the only course of action to contain disease outbreaks. Outbreaks generally occur in fry at temperatures between 10 and 15 °C. Recently outbreaks in larger fish have given added impetus to the development of a vaccine which can provide long term protection from this highly heterogeneous pathogen. Most fish injectable vaccines are formulated with oil emulsion adjuvants to induce strong and long lasting immunity, but which are known to cause side effects. Alternative adjuvants are currently sought to minimise these adverse effects. The current study was performed to assess the efficacy of a polyvalent, whole cell vaccine containing formalin-inactivated F. psychrophilum to induce protective immunity in Atlantic salmon. The vaccine was formulated with an adjuvant containing squalene and aluminium hydroxide, and was compared to a vaccine formulated with a traditional oil adjuvant, Montanide ISA 760VG, and a non-adjuvanted vaccine. Duplicate groups of salmon (23.5 ± 6.8 g) were vaccinated with each of the vaccine formulations or phosphate buffered saline by intraperitoneal injection. Fish were challenged by intramuscular injection with F. psychrophilum six weeks post-vaccination to test the efficacy of the vaccines. Cumulative mortality reached 70% in the control salmon, while the groups of salmon that received vaccine had significantly lower mortality than the controls (p = 0.0001), with no significant difference in survival between vaccinated groups. The squalene/alum adjuvant was safe, more readily metabolised by the fish and induced less histopathological changes than the traditional oil adjuvant.

Melatonin enhances responsiveness to Dichelobacter nodosus vaccine in sheep and increases peripheral blood CD4 T lymphocytes and IgG-expressing B lymphocytes.

The immunomodulatory functions mediated by melatonin support its use as vaccine adjuvant. Previously, we have demonstrated that melatonin enhances antibody responses in sheep vaccinated against Dichelobacter nodosus. Here, we analyze the effect of melatonin on T and B lymphocyte subsets in peripheral blood of sheep vaccinated against D. nodosus. We also compare the use of melatonin in implants and in injections. Melatonin administration either as implants or by injection produced higher antibody titers against A1 and C serotypes compared to those animals that received only the vaccine. These results support the use of melatonin as an adjuvant in vaccination against D. nodosus. Firstly, melatonin induces higher antibody titer than the vaccine alone, secondly, melatonin increase IgG+ B lymphocytes and CD4+ T lymphocytes in vaccinated sheep. These results suggest that melatonin enhances T CD4 cell activation and subsequently secondary humoral immune responses. Further studies are required to determine the mechanism underlining the immunomodulatory role of melatonin in the context of vaccination.

Clinical responses in cows vaccinated with a developed prototype killed Staphylococcus aureus mastitis vaccine.

Mastitis is an inflammatory condition of the udder that occurs as a result of the release of leucocytes into the udder in a response to bacterial invasion. The major causes of mastitis are an array of gram positive and negative bacteria, however, algae, virus, fungi, mechanical or thermal injury to the gland have also been identified as possible causes. Mastitis vaccines are yet to be developed using Malaysian local isolate of bacteria. The objective of the present experimental trial was to develop a monovalent vaccine against mastitis using S. aureus of Malaysian isolate and to evaluate the clinical responses such as temperature, respiratory rates and heart rates in vaccinated cows. S. aureus is a major causative bacteria in clinical and subclinical types of mastitis in cows. Four concentrations of the bacterin (106, 107, 108 and 109 cfu/ml of the local isolate of S. aureus) were prepared using Aluminium potassium sulfate adjuvant. Thirty cows were grouped into four treatment groups (B, C, D and E) with a fifth group as control (A). These groups were vaccinated intramuscularly(IM) with the prepared monovalent vaccine and its influence on the vital signs were intermittently measured. The mean of rectal temperature was significantly different (p˂ 0.05) at 0hr Post Vaccination [1]" in groups D and E (39.5 ±â€¯0.15 °C and 39.4 ±â€¯0.15 °C respectively) and at 3 h PV in groups C, D and E (39.8 ±â€¯0.14 °C, 39.9 ±â€¯0.14 °C and 40.3 ±â€¯0.14 °C respectively) compared to the control group. This indicated a sharp increased rectal temperatures between 0hr and 3 h PV in groups C, D and E which later declined at 24 h PV. The mean of rectal temperature of group E was significantly different (p˂ 0.05) at weeks 1 and 2 PV (39.87 ±â€¯0.19 °C and 39.80 ±â€¯0.18 °C respectively) compared to the control group. The mean of heart rate was significantly different (p˂ 0.05) at week 1 PV in groups D and E (83.0 ±â€¯3.8 beats/minute and 80.0 ±â€¯3.8 °C respectively) compared to control. A trending decrease was however observed in heart rates of group E from weeks through 4 PV and in group D from weeks 1 through 3 PV. The mean of respiratory rates was significantly different (p˂ 0.05) at week 3 PV in group B and D (31.0 ±â€¯1.2 breaths/minute and 28.0 ±â€¯1.2 breaths/minute) compared to control. In conclusion, this study highlights responses of these vital signs due to vaccination against S. aureus causing mastitis in cows. To the best of our knowledge the findings of this study adds value to the shallow literature on vital signs alterations in cows vaccinated against mastitis as elevated levels of temperature and heart rates of group D and E indicated obvious response.

Pasteurella multocida inactivated with ferric chloride and adjuvanted with bacterial DNA is a potent and efficacious vaccine in Balb/c mice.

PURPOSE: Pasteurella multocida (P. multocida) is a principal pathogen of domestic animals and an opportunistic pathogen of humans. It is the causative agent of pneumonia and haemorrhagic septicaemia in cattle, sheep and goats, fowl cholera in chickens and progressive atrophic rhinitis in swine. In this study, we investigated the humoral and cellular immune responses and protective immunity conferred by an iron-inactivated vaccine with bacterial DNA (IIV+bDNA) as an adjuvant in mice. METHODOLOGY: P. multocida was grown in BHI broth, inactivated with formalin and FeCl3 and adjuvanted with alum and bDNA. Mice were immunized with two whole-cell inactivated vaccine doses 2 weeks apart. The animals were challenged 4 weeks after booster immunization. Immunogens (vaccines and bDNA) posed no safety problems when mice were injected subcutaneously (s/c) with these preparations. The serum antibody titres were tested by ELISA. At 28 days post immunization, cell-mediated immunity responses were determined. The responses were measured by assay of IL-6 and IL-12 in lymphocyte spleen culture supernatants. RESULTS: ELISA results showed that the levels of antibodies in iron inactivated with bDNA adjuvant groups were higher than in the formalin inactivated with alum adjuvant vaccine group. The protection rate of IIV+bDNA adjuvant vaccine was superior to that of the other vaccines and it protected 100 % of the challenge group mice. Following immunization, bDNA promoted increased production of interleukins compared to the control groups. CONCLUSION: These studies indicate that bDNA is effective as an immune adjuvant, and along with stimulatory bDNA represent promising new humoral and cellular immune enhancers for vaccination applications. In addition, this vaccine is able to provide long-term protection against infection.

Live Attenuated Tularemia Vaccines for Protection Against Respiratory Challenge With Virulent F. tularensis subsp. tularensis.

Francisella tularensis is the causative agent of tularemia and a Tier I bioterrorism agent. In the 1900s, several vaccines were developed against tularemia including the killed "Foshay" vaccine, subunit vaccines comprising F. tularensis protein(s) or lipoproteins(s) in an adjuvant formulation, and the F. tularensis Live Vaccine Strain (LVS); none were licensed in the U.S.A. or European Union. The LVS vaccine retains toxicity in humans and animals-especially mice-but has demonstrated efficacy in humans, and thus serves as the current gold standard for vaccine efficacy studies. The U.S.A. 2001 anthrax bioterrorism attack spawned renewed interest in vaccines against potential biowarfare agents including F. tularensis. Since live attenuated-but not killed or subunit-vaccines have shown promising efficacy and since vaccine efficacy against respiratory challenge with less virulent subspecies holarctica or F. novicida, or against non-respiratory challenge with virulent subsp. tularensis (Type A) does not reliably predict vaccine efficacy against respiratory challenge with virulent subsp. tularensis, the route of transmission and species of greatest concern in a bioterrorist attack, in this review, we focus on live attenuated tularemia vaccine candidates tested against respiratory challenge with virulent Type A strains, including homologous vaccines derived from mutants of subsp. holarctica, F. novicida, and subsp. tularensis, and heterologous vaccines developed using viral or bacterial vectors to express F. tularensis immunoprotective antigens. We compare the virulence and efficacy of these vaccine candidates with that of LVS and discuss factors that can significantly impact the development and evaluation of live attenuated tularemia vaccines. Several vaccines meet what we would consider the minimum criteria for vaccines to go forward into clinical development-safety greater than LVS and efficacy at least as great as LVS, and of these, several meet the higher standard of having efficacy ≥LVS in the demanding mouse model of tularemia. These latter include LVS with deletions in purMCD, sodBFt , capB or wzy; LVS ΔcapB that also overexpresses Type VI Secretion System (T6SS) proteins; FSC200 with a deletion in clpB; the single deletional purMCD mutant of F. tularensis SCHU S4, and a heterologous prime-boost vaccine comprising LVS ΔcapB and Listeria monocytogenes expressing T6SS proteins.

[Different aluminum adjuvants significantly enhances the effect of immunization on Brucella Omp31].

Objective To investigate the effect of aluminum phosphate (AP) and aluminum hydroxide (AH) as adjuvants on Brucella outer membrane protein 31 (Omp31) in inducing humoral and cellular immune responses and immune protection. Methods AP and AH adjuvants were prepared and separately mixed with Brucella Omp31 protein to measure the adsorption rates. The AP- and AH-absorbed Omp31 protein were intraperitoneally injected into BLAB/c mice at 0, 2, and 4 weeks, and meanwhile, unabsorbed Omp31 protein and PBS were used as controls. The levels of serum IgG, IgG1, IgG2a and genital tract secretion sIgA were determined by ELISA at 0, 2, 4 and 6 weeks. Spleen cells were collected for culture at 6 weeks, and the cells were stimulated by Omp31 for 48 hours followed by the analysis of IFN-γ and IL-10 levels in the supernatants by ELISA, and the determination of lymphocyte proliferation by CCK-8 assay. The mice were challenged with Brucella at 6 weeks, and bacterial content in spleen tissue was determined 1 and 2 weeks later. Results AP and AH could absorb over 70% and 85% of the Omp31 protein, respectively, for solutions at all the tested concentrations. ELISA suggested that serum IgG, IgG1, IgG2a and genital tract sIgA levels peaked 2 weeks after the last immunization for both AP and AH groups, and antibody level was higher in the AP and AH groups than the control groups, and higher in the AH group than in the AP group. CCK-8 assay showed that the proliferating rate of lymphocytes induced by the AH group was significantly higher than that by the AP group, and the AH group also showed significantly higher IFN-γ level in the supernatant than the AP group, but no significant difference in IL-10 level. The AH group had remarkably lower bacterial load in the spleen than the AP group 2 weeks after challenged by Brucella 16M strain. Conclusion Both AP and AH adjuvants effectively enhanced immunogenicity and immune protection of the Brucella Omp31 protein, and AH was superior to AP in this respect.

Humanized Mice for the Evaluation of Francisella tularensis Vaccine Candidates.

Francisella tularensis (FT), a highly infectious pathogen, is considered to be a potential biological weapon owing to the current lack of a human vaccine against it. Tul4 and FopA, both outer membrane proteins of FT, play an important role in the bacterium's immunogenicity. In the present study, we evaluated the immune response of mice-humanized with human CD34+ cells (hu-mice)-to a cocktail of recombinant Tul4 and FopA (rTul4 and rFopA), which were codon-optimized and expressed in Escherichia coli. Not only did the cocktail-immunized hu-mice produce a significant human immunoglobulin response, they also exhibited prolonged survival against an attenuated live vaccine strain as well as human T cells in the spleen. These results suggest that the cocktail of rTul4 and rFopA had successfully induced an immune response in the hu-mice, demonstrating the potential of this mouse model for use in the evaluation of FT vaccine candidates.