Search

Melioidosis, caused by the intracellular bacterial pathogen and Tier 1 select agent Burkholderia pseudomallei (Bp), is a highly fatal disease endemic in tropical areas. No licensed vaccine against melioidosis exists. In preclinical vaccine studies, demonstrating protection against respiratory infection in the highly sensitive BALB/c mouse has been especially challenging. To address this challenge, we have used a safe yet potent live attenuated platform vector, LVS ΔcapB, previously used successfully to develop vaccines against the Tier 1 select agents of tularemia, anthrax, and plague, to develop a melioidosis vaccine. We have engineered melioidosis vaccines (rLVS ΔcapB/Bp) expressing multiple immunoprotective Bp antigens among type VI secretion system proteins Hcp1, Hcp2, and Hcp6, and membrane protein LolC. Administered intradermally, rLVS ΔcapB/Bp vaccines strongly protect highly sensitive BALB/c mice against lethal respiratory Bp challenge, but protection is overwhelmed at very high challenge doses. In contrast, administered intranasally, rLVS ΔcapB/Bp vaccines remain strongly protective against even very high challenge doses. Under some conditions, the LVS ΔcapB vector itself provides significant protection against Bp challenge, and consistent with this, both the vector and vaccines induce humoral immune responses to Bp antigens. Three-antigen vaccines expressing Hcp6-Hcp1-Hcp2 or Hcp6-Hcp1-LolC are among the most potent and provide long-term protection and protection even with a single intranasal immunization. Protection via the intranasal route was either comparable to or statistically significantly better than the single-deletional Bp mutant Bp82, which served as a positive control. Thus, rLVS ΔcapB/Bp vaccines are exceptionally promising safe and potent melioidosis vaccines.ImportanceMelioidosis, a major neglected disease caused by the intracellular bacterial pathogen Burkholderia pseudomallei, is endemic in many tropical areas of the world and causes an estimated 165,000 cases and 89,000 deaths in humans annually. Moreover, B. pseudomallei is categorized as a Tier 1 select agent of bioterrorism, largely because inhalation of low doses can cause rapidly fatal pneumonia. No licensed vaccine is available to prevent melioidosis. Here, we describe a safe and potent melioidosis vaccine that protects against lethal respiratory challenge with B. pseudomallei in a highly sensitive small animal model-even a single immunization is highly protective, and the vaccine gives long-term protection. The vaccine utilizes a highly attenuated replicating intracellular bacterium as a vector to express multiple key proteins of B. pseudomallei; this vector platform has previously been used successfully to develop potent vaccines against other Tier 1 select agent diseases including tularemia, anthrax, and plague.

Oral delivery of an inexpensive COVID-19 (coronavirus disease 2019) vaccine could dramatically improve immunization rates, especially in low- and middle-income countries. Previously, we described a potential universal COVID-19 vaccine, rLVS ΔcapB/MN, comprising a replicating bacterial vector, LVS (live vaccine strain) ΔcapB, expressing the highly conserved SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) membrane and nucleocapsid (N) proteins, which, when administered intradermally or intranasally, protects hamsters from severe COVID-19-like disease after high-dose SARS-CoV-2 respiratory challenge. Here, we show that oral administration of the vaccine also protects against high-dose SARS-CoV-2 respiratory challenge; its protection is comparable to that of intradermal, intranasal, or subcutaneous administration. Hamsters were protected against severe weight loss and lung pathology and had reduced oropharyngeal and lung virus titers. Protection against weight loss and histopathology by the vaccine, which in mice induces splenic and lung cell interferon gamma in response to N protein stimulation, was correlated in hamsters with pre-challenge serum anti-N TH1-biased IgG (IgG2/3). Thus, rLVS ΔcapB/MN has potential as an oral universal COVID-19 vaccine. IMPORTANCE The COVID-19 pandemic continues to rage into its fourth year worldwide. To protect the world's population most effectively from severe disease, hospitalization, and death, a vaccine is needed that is resistant to rapidly emerging viral variants of the causative agent SARS-CoV-2, inexpensive to manufacture, store, and transport, and easy to administer. Ideally, such a vaccine would be capable of oral administration, especially in resource-poor countries of the world where there are shortages of needles, syringes and trained personnel to administer injectable vaccines. Here, we show that oral administration of a bacterium-vectored vaccine meeting all these criteria protects naturally susceptible Syrian hamsters from severe COVID-19-like disease, including severe weight loss and lung pathology, after high-dose SARS-CoV-2 respiratory challenge. As the vaccine is based upon inducing immunity to highly conserved SARS-CoV-2 membrane and nucleocapsid proteins, as opposed to the rapidly mutating Spike protein, it should remain resistant to newly emerging SARS-CoV-2 variants.

To generate an inexpensive readily manufactured COVID-19 vaccine, we employed the LVS ΔcapB vector platform, previously used to generate potent candidate vaccines against Select Agent diseases tularemia, anthrax, plague, and melioidosis. Vaccines expressing SARS-CoV-2 structural proteins are constructed using the LVS ΔcapB vector, a highly attenuated replicating intracellular bacterium, and evaluated for efficacy in golden Syrian hamsters, which develop severe COVID-19-like disease. Hamsters immunized intradermally or intranasally with a vaccine co-expressing the Membrane and Nucleocapsid proteins and challenged 5 weeks later with a high dose of SARS-CoV-2 are protected against severe weight loss and lung pathology and show reduced viral loads in the oropharynx and lungs. Protection correlates with anti-Nucleocapsid antibody. This potent vaccine should be safe; inexpensive; easily manufactured, stored, and distributed; and given the high homology between Membrane and Nucleocapsid proteins of SARS-CoV and SARS-CoV-2, potentially serve as a universal vaccine against the SARS subset of pandemic causing β-coronaviruses.

An inexpensive readily manufactured COVID-19 vaccine that protects against severe disease is needed to combat the pandemic. We have employed the LVS Δ capB vector platform, previously used successfully to generate potent vaccines against the Select Agents of tularemia, anthrax, plague, and melioidosis, to generate a COVID-19 vaccine. The LVS Δ capB vector, a replicating intracellular bacterium, is a highly attenuated derivative of a tularemia vaccine (LVS) previously administered to millions of people. We generated vaccines expressing SARS-CoV-2 structural proteins and evaluated them for efficacy in the golden Syrian hamster, which develops severe COVID-19 disease. Hamsters immunized intradermally or intranasally with a vaccine co-expressing the Membrane (M) and Nucleocapsid (N) proteins, then challenged 5-weeks later with a high dose of SARS-CoV-2, were protected against severe weight loss and lung pathology and had reduced viral loads in the oropharynx and lungs. Protection by the vaccine, which induces murine N-specific interferon-gamma secreting T cells, was highly correlated with pre-challenge serum anti-N TH1-biased IgG. This potent vaccine against severe COVID-19 should be safe and easily manufactured, stored, and distributed, and given the high homology between MN proteins of SARS-CoV and SARS-CoV-2, has potential as a universal vaccine against the SARS subset of pandemic causing β-coronaviruses.

Initial transmission of severe acute respiratory syndrome virus-2 (SARS-CoV-2) was highest in densely populated regions of Kenya. Transmission gradually trickled down to the less densely populated, remote and underserved regions such as the pastoral regions of Kajiado County which are characterized by poor healthcare systems. Molecular assays that were pivotal for COVID-19 diagnosis were not available in these regions. Serology is an alternative method for retrospectively tracking the transmission of SARS-CoV-2 in such populations. Dry blood spots (DBS) were prepared from consenting patients attending six health facilities in Kajiado County from March 2020 to March 2022. Upon elution, we conducted an enzyme-linked immunosorbent assay (ELISA) for the detection of SARS-Cov-2 IgG antibodies. Of the 908 DBSs we analyzed, 706 (78%) were from female participants. The overall seropositivity to SARS-Cov-2 antibodies was 7.3% (95% CI 5.7–9.1). The elderly (over 60 years) and male participants had a high likelihood of testing positive for SAR-CoV-2 infections. Mashuru (15.6%, 14/90) and Meto (15%, 19/127) health facilities registered the highest proportion of seropositive participants. Evidence of SARS-CoV-2 transmission among pastoralists in the remote and underserved regions of Kajiado County was established by DBS sampling and serologic testing. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD) has become a major concern among those involved in managing wild and captive cervid populations. CWD is a fatal, highly transmissible spongiform encephalopathy caused by an abnormally folded protein, called a prion. Prions are present in a number of tissues, including feces and urine in CWD infected animals, suggesting multiple modes of transmission, including animal-to-animal, environmental, and by fomite. CWD management is complicated by the lack of practical, non-invasive, live-animal screening tests. Recently, there has been a focus on how the volatile odors of feces and urine can be used to discriminate between infected and noninfected animals in several different species. Such a tool may prove useful in identifying potentially infected live animals, carcasses, urine, feces, and contaminated environments. Toward this goal, dogs were trained to detect and discriminate CWD infected individuals from non-infected deer in a laboratory setting. Dogs were tested with novel panels of fecal samples demonstrating the dogs' ability to generalize a learned odor profile to novel odor samples based on infection status. Additionally, dogs were transitioned from alerting to fecal samples to an odor profile that consisted of CWD infection status with a different odor background using different sections of gastrointestinal tracts. These results indicated that canine biodetectors can discriminate the specific odors emitted from the feces of non-infected versus CWD infected white-tailed deer as well as generalizing the learned response to other tissues collected from infected individuals. These findings suggest that the health status of wild and farmed cervids can be evaluated non-invasively for CWD infection via monitoring of volatile metabolites thereby providing an effective tool for rapid CWD surveillance. [ABSTRACT FROM AUTHOR]

Anthrax, caused by Bacillus anthracis, is a zoonotic disease of global importance because of its ecologic effects on wildlife and free-ranging livestock and resulting economic impact on farmers and herders, [...]

BackgroundSurgical site infections (SSI) poses significant risk following spinal instrumentation surgery. The 2013 North American Spine Society (NASS) Evidence-Based Clinical Guidelines found that the incidence of SSI in spine surgery ranged from 0.7-10%, with higher rates with medical comorbidities. National guidelines currently recommend first-generation cephalosporins as first line prophylaxis. Due to an increase in MRSA cases in our institution, a combined antibiotic strategy using vancomycin IV, standard prophylactic antibiotics, and vancomycin powder was implemented for all spinal instrumentation surgeries.MethodsAll spinal instrumentation surgeries performed at this institution from 2013-2016 were identified. Chart review was then performed to identify the inclusion and exclusion criteria, demographic data, diagnosis, type of surgery performed, and bacterial culture results. Rates of SSI, as defined by the Center for Disease Control (CDC), were calculated and antibiotic resistance was determined. As control, SSIs were identified and reviewed from 2010, prior to the implementation of the combined strategy.ResultsOne thousand and seventy four subjects were identified in the combined cohort. Mean age was 52.3 years, 540 males (50.2%), 534 females (49.8%). There were 960 primary surgeries (89.4%), 114 cases revision surgeries (10.6%). Cervical myelopathy (27.9%), lumbar stenosis (16.2%), lumbar spondylolisthesis (14.0%), and scoliosis (pediatric and adult)/deformity (13.7%) were leading diagnoses. The standard prophylactic antibiotic was cefazolin IV in 524 cases (48.8%), gentamicin IV in 526 cases (49.0%), vancomycin powder was used in 72.3% of cases. Four SSI cases out of 1,074 were identified (0.37%), 3 deep and 1 superficial, with no antibiotic resistance. In the control group, there were 11 infections of 892 cases (1.23%). There were significantly lower rates of SSI in the combined group versus control (P=0.05).ConclusionsThe combined antibiotic strategy led to low SSI rates in this retrospective case control study. Limitations of this study include retrospective design and small sample size. A large multicenter randomized clinical trial may provide further insight in the effectiveness of this strategy. Level of evidence 3. Clinical relevance: the combined antibiotic protocol may be considered in institutions with concern for SSI and methicillin resistant infections associated with spinal instrumentation surgeries.

Bacillus anthracis, Yersinia pestis, and Francisella tularensis are the causative agents of Tier 1 Select Agents anthrax, plague, and tularemia, respectively. Currently, there are no licensed vaccines against plague and tularemia and the licensed anthrax vaccine is suboptimal. Here we report F. tularensis LVS ΔcapB (Live Vaccine Strain with a deletion in capB)- and attenuated multi-deletional Listeria monocytogenes (Lm)-vectored vaccines against all three aforementioned pathogens. We show that LVS ΔcapB- and Lm-vectored vaccines express recombinant B. anthracis, Y. pestis, and F. tularensis immunoprotective antigens in broth and in macrophage-like cells and are non-toxic in mice. Homologous priming-boosting with the LVS ΔcapB-vectored vaccines induces potent antigen-specific humoral and T-cell-mediated immune responses and potent protective immunity against lethal respiratory challenge with all three pathogens. Protection against anthrax was far superior to that obtained with the licensed AVA vaccine and protection against tularemia was comparable to or greater than that obtained with the toxic and unlicensed LVS vaccine. Heterologous priming-boosting with LVS ΔcapB- and Lm-vectored B. anthracis and Y. pestis vaccines also induced potent protective immunity against lethal respiratory challenge with B. anthracis and Y. pestis. The single vaccine platform, especially the LVS ΔcapB-vectored vaccine platform, can be extended readily to other pathogens.

The rapid global expansion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease (COVID-19), has been unprecedented in modern history. Although the original human infection(s) were potentially [...]

Since 1997, highly pathogenic avian influenza viruses of the H5N1 subtype have been transmitted from avian hosts to humans. The severity of H5N1 infection in humans, as well as the sporadic nature of H5N1 outbreaks, both geographically and temporally, make generation of an effective vaccine a global public health priority. An effective H5N1 vaccine must ultimately provide protection against viruses from diverse clades. Toll-like receptor (TLR) agonist adjuvant formulations have a demonstrated ability to broaden H5N1 vaccine responses in pre-clinical models. However, many of these agonist molecules have proven difficult to develop clinically. Here, we describe comprehensive adjuvant formulation development of the imidazoquinoline TLR-7/8 agonist 3M-052, in combination with H5N1 hemagglutinin (HA) based antigens. We find that 3M-052 in multiple formulations protects both mice and ferrets from lethal H5N1 homologous virus challenge. Furthermore, we conclusively demonstrate the ability of 3M-052 adjuvant formulations to broaden responses to H5N1 HA based antigens, and show that this broadening is functional using a heterologous lethal virus challenge in ferrets. Given the extensive clinical use of imidazoquinoline TLR agonists for other indications, these studies identify multiple adjuvant formulations which may be rapidly advanced into clinical trials in an H5N1 vaccine.

PurposeAnterior cruciate ligament (ACL) rupture is increasingly common in adolescents. Time between ACL rupture and surgical reconstruction, surgical wait time, is related to concurrent meniscal tear incidence and possibly tear pattern. This study defines the relationship between meniscal tear characteristics and surgical wait time in adolescents with ACL rupture.MethodsOne-hundred and twenty-one consecutive adolescent (median age 16.1 years, range 9-19 years) ACL rupture patients undergoing primary ACL reconstruction were studied. All had documented surgical wait time, preoperative and 6-month post-operative outcome (Lysholm and pedi-IKDC) scores, and intraoperative meniscus tear characteristics. Meniscal tear severity was graded according to the Lawrence and Anderson system: non-surgical: grade 1; reparable: grade 2-3; irreparable: grade 4-5. Significant tears were defined as at least grade 2.ResultsAverage age at surgery was 16.1 years. 48.7 % had surgical wait time greater than 6 months. 42.5 % of menisci were torn. With surgical wait time 6 months, medial tear incidence increased (50 vs 21 %, p 6 months. Public insurance was a risk factor for longer surgical wait time and meniscus tear.

This paper discusses whether the Bitcoin exchange-traded fund (ETF), which tracks the value of Bitcoin, improves equity portfolios, by using a robust portfolio performance analysis. The equity portfolio is represented by an ETF that tracks the Standard & Poor's 500. We use data from a turbulent investment period within the coronavirus pandemic, to study the diversification benefits of Bitcoin. We compare the performances of diverse portfolios composed of both ETFs, which include 40 classical dynamic volatility model-based portfolios and 900 score-driven portfolios. For the score-driven portfolios, the dynamic association is modelled by score-driven Clayton, rotated Clayton, Gumbel, rotated Gumbel and Student's t copulas. We compare portfolio strategies using the model confidence set test. We find that score-driven portfolios outperform classical volatility model-based portfolios and the equity portfolio. Our results may provide suggestions for cryptocurrency investors on portfolio optimization and may also have policy implications for regulators and policymakers. [ABSTRACT FROM AUTHOR]

A safer and more effective vaccine than the unlicensed Francisella tularensis Live Vaccine Strain (LVS) is needed to protect against the biowarfare agent F. tularensis. Previously, we developed an LVS ΔcapB mutant that is significantly safer than LVS and provides potent protective immunity against F. tularensis respiratory challenge when administered intranasally but limited protection when administered intradermally unless as part of a prime-boost vaccination strategy. To improve the immunogenicity and efficacy of LVS ΔcapB, we developed recombinant LVS ΔcapB (rLVS ΔcapB) strains overexpressing various F. tularensis Francisella Pathogenicity Island (FPI) proteins - IglA, IglB and IglC, and a fusion protein (IglABC) comprising immunodominant epitopes of IglA, IglB, and IglC downstream of different Francisella promoters, including the bacterioferritin (bfr) promoter. We show that rLVS ΔcapB/bfr-iglA, iglB, iglC, and iglABC express more IglA, IglB, IglC or IglABC than parental LVS ΔcapB in broth and in human macrophages, and stably express FPI proteins in macrophages and mice absent antibiotic selection. In response to IglC and heat-inactivated LVS, spleen cells from mice immunized intradermally with rLVS ΔcapB/bfr-iglC or bfr-iglABC secrete greater amounts of interferon-gamma and/or interleukin-17 than those from mice immunized with LVS ΔcapB, comparable to those from LVS-immunized mice. Mice immunized with rLVS ΔcapB/bfr-iglA, iglB, iglC or iglABC produce serum antibodies at levels similar to LVS-immunized mice. Mice immunized intradermally with rLVS ΔcapB/bfr-iglABC and challenged intranasally with virulent F. tularensis Schu S4 survive longer than sham- and LVS ΔcapB-immunized mice. Mice immunized intranasally with rLVS ΔcapB/bfr-iglABC - but not with LVS - just before or after respiratory challenge with F. tularensis Schu S4 are partially protected; protection is correlated with induction of a strong innate immune response. Thus, rLVS ΔcapB/bfr-iglABC shows improved immunogenicity and protective efficacy compared with parental LVS ΔcapB and, in contrast to LVS, has partial efficacy as immediate pre- and post-exposure prophylaxis.

Osteocytes regulate bone turnover and mineralization in chronic kidney disease. As osteocytes are derived from osteoblasts, alterations in osteoblast function may regulate osteoblast maturation, osteocytic transition, bone turnover, and skeletal mineralization. Thus, primary osteoblast-like cells were cultured from bone chips obtained from 24 pediatric ESKD patients. RNA expression in cultured cells was compared with RNA expression in cells from healthy individuals, to RNA expression in the bone core itself, and to parameters of bone histomorphometry. Proliferation and mineralization rates of patient cells were compared with rates in healthy control cells. Associations were observed between bone osteoid accumulation, as assessed by bone histomorphometry, and bone core RNA expression of osterix, matrix gla protein, parathyroid hormone receptor 1, and RANKL. Gene expression of osteoblast markers was increased in cells from ESKD patients and signaling genes including Cyp24A1, Cyp27B1, VDR, and NHERF1 correlated between cells and bone cores. Cells from patients with high turnover renal osteodystrophy proliferated more rapidly and mineralized more slowly than did cells from healthy controls. Thus, primary osteoblasts obtained from patients with ESKD retain changes in gene expression ex vivo that are also observed in bone core specimens. Evaluation of these cells in vitro may provide further insights into the abnormal bone biology that persists, despite current therapies, in patients with ESKD.