Effectiveness of oral cholera vaccine in preventing cholera among fishermen in Lake Chilwa,Malawi: A case-control study

BackgroundIn response to a cholera outbreak among mobile, difficult-to-reach fishermen on Lake Chilwa, Malawi in 2016, a novel vaccine distribution strategy exploited the proven vaccine thermostability. Fishermen, while taking the first vaccine dose under supervision, received the second dose in a sealed bag, and were told to drink it two weeks later. This study assessed short-term vaccine protection of this strategy.MethodsPatients with diarrhoea admitted to health facilities around lake were interviewed and a stool sample collected for PCR testing. Vaccine effectiveness was assessed in a case-control test-negative design by comparing cases (PCR-positive for V. cholerae O1) and controls (patients with diarrhoea but PCR-negative) and with the screening method that compared the proportions of vaccinated among cholera cases versus the general fishermen population.ResultsOf 145 study participants, 120 were fishermen living on the lake. Vaccine effectiveness at three-months was 90.0% [95% CI: 38.8; 98.4] among fishermen and 83.3% [95% CI: 20.8; 96.5] among all participants in the case-control test-negative design, and 97.5% [95% CI: 90.9; 99.3] with the screening method.ConclusionThis strategy was effective in providing short-term protection in fishermen against cholera. Further research is needed to determine the adding value of the second dose and to identify the optimal vaccination strategies for different contexts.     

Production of laccase from Pleurotus florida using agro‐wastes and efficient decolorization of Reactive blue 198

Pleurotus florida NCIM 1243 produced laccase as the dominant lignolytic enzyme during the dye decolorization. Banana peel was the best substrate for extracellular laccase production under solid state fermentation when compared to mandarin peel and cantaloupe peel. The maximum activity of laccase (5.4 U/g) was detected on the 10 day. The ratio of banana peel: mandarin peel: cantaloupe peel (5:2:3) showed increased production of laccase (6.8 U/g). P. florida produced two extracellular laccase isoenzymes (L1 and L2). The half life of laccase at 60 °C was 2 h and at 4 h it retained 25% residual activity. P. florida laccase showed high thermostability and an interesting difference was noticed in the behavior of laccase isoenzymes at different temperature. The L1 isoenzyme of laccase showed remarked thermostability at 60 °C in the native PAGE when compared to L2 isoenzyme. The optimum pH, temperature and enzyme concentration for maximum decolorization was found to be 4.5, 60 °C and 1.2 U/ml, respectively. Partially purified laccase enzyme showed excellent decolorization activity to Reactive blue 198. The maximum decolorization (96%) was observed at lower dye concentrations (50–100 ppm) which decreased markedly when the dye concentration was increased beyond 150 ppm. The thermostable laccase of P. florida could be effectively used to decolorize the synthetic dyes in the textile effluent and other biotechnological applications. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Transcutaneous immunization with Intercell's vaccine delivery system

Transcutaneous immunization (TCI) has become an attractive alternate route of immunization due to increase understanding of the skin immune system and to recent technical innovations in skin patch delivery systems. Basic principles of TCI have been demonstrated in animal and human studies, covering a variety of bacterial, viral, and cancer diseases. At Intercell, we have advanced two major platforms of TCI: 1) a needle-free vaccine delivery patch (VDP) and 2) a vaccine enhancement patch (VEP). Simplified, the VDP contains an antigen with or without an adjuvant that is administered on the skin; while the VEP contains only the adjuvant and is used in combination with an injected vaccine. In many of our TCI studies, the VDP or VEP is routinely applied on pretreated skin, in which the stratum corneum has been partially removed by mild abrasion. Recently, we have achieved technical breakthroughs in formulating and stabilizing vaccines in a dry patch format. For instance, a microplate-based screening process has been implemented to rapidly identify excipients, singularly or in combination, to stabilize biological macromolecules in patch blend formulations. A second technical innovation is our nonwoven (patch) disc matrix-supported drying technology, which allows efficient drying of our patch formulation blend to produce dry stable dosage forms of VDP or VEP. The low cost and the facileness in the manufacturing of VDP (or VEP) combined with the development of thermostable dry patches should improve the supply chain efficiency and reduce the dependence on cold chain.     

Thermostability of Human Immunodeficiency Virus (HIV-1) in a Liquid Matrix Is Far Higher than That of an Ecotropic Murine Leukemia Virus

For prevention of HIV infection, which is fatal to man and has no known remedy, sterilization of contaminated materials is particularly important. Before applying any sterilization procedures, they have to be checked by accurately following the kinetics of plaque reduction. Though this is almost self-evident, such studies have been few. Here, a microplaque assay of HIV is established using HPB-ALL human T-cells immobilized on a poly-L-lysine-coated plastic dish. This assay was used to compare the ultraviolet and heat inactivation kinetics of HIV (titrated by this method) with those of Moloney murine leukemia virus (MLV) in a liquid matrix. Though the ultraviolet sensitivities of these viruses were identical (D₁₀=2,800 ergs/mm²), HIV was far more resistant to high temperatures (50°C 70°C) than MLV. This implies that these two viruses have different virion structures, though both are members of retroviridae. The higher thermostability of HIV should be taken into account when HIV-contaminated materials are handled.     

福建11种海洋贝类凝集素的研究

用绵羊、家兔、家鸡、麻鸭和人的A,B,AB,O型血等8种红细胞对11种海洋贝类的凝集素进行凝血活性检测,同时进行凝集素的糖抑制和热稳定性试验,结果表明,有10种贝类凝集素对绵羊红细胞有凝集活性,有6种对家兔红细胞有凝集活性,对家鸡,麻鸭和人B型血细胞铡全无凝集活性,对人的其它3种血型的细细胞只有个别的有凝集活性,某些种类的凝集对兔红细胞的凝集活性可分别被一种或几种糖抑制,6种贝类的凝集素在90度,10min热处理后仍然对兔红细胞有凝集活性,显示出较高的热稳定性     

A winged-helix protein from Sulfolobus turreted icosahedral virus points toward stabilizing disulfide bonds in the intracellular proteins of a hyperthermophilic virus

Sulfolobus turreted icosahedral virus (STIV) was the first non-tailed icosahedral virus to be isolated from an archaeal host. Like other archaeal viruses, its 37 open reading frames generally lack sequence similarity to genes with known function. The roles of the gene products in this and other archaeal viruses are thus largely unknown. However, a protein's three-dimensional structure may provide functional and evolutionary insight in cases of minimal sequence similarity. In this vein, the structure of STIV F93 reveals a homodimer with strong similarity to the winged-helix family of DNA-binding proteins. Importantly, an interchain disulfide bond is found at the dimer interface, prompting analysis of the cysteine distribution in the putative intracellular proteins of the viral proteome. The analysis suggests that intracellular disulfide bonds are common in cellular STIV proteins, where they enhance the thermostability of the viral proteome.     

离心力辅助硫酸氢氯吡格雷晶型I的制备及其稳定性(英文)

硫酸氢氯吡格雷的几个已报道的晶型中,相对于晶型II,晶型I的热稳定性较差,在高温高湿条件下会自发地转变为晶型I I,因而晶型I在生产中难以得到热稳定性好的产品。本文提出利用离心力辅助析晶的方法能生产出高纯度,稳定性好的晶型I产品。所得到的产品分别用粉末X射线衍射仪(PXRD),差示扫描热量仪(DSC)和扫描电镜显微镜(SEM)进行了表征。结果显示:离心力辅助析晶比用传统反溶剂析晶方法得到的晶型I结晶度有明显增加,晶粒生长得更大更完整。通过长期稳定性实验,证明新工艺所得到的产品具有较好的热稳定性,在高温高湿的环境下能长时间储存不变质。     

A user-friendly and scalable process to prepare a ready-to-use inactivated vaccine: The example of heartwater in ruminants under tropical conditions

The use of cheap and thermoresistant vaccines in poor tropical countries for the control of animal diseases is a key issue. Our work aimed at designing and validating a process for the large-scale production of a ready-to-use inactivated vaccine for ruminants. Our model was heartwater caused by the obligate intracellular bacterium Ehrlichia ruminantium (ER). The conventional inactivated vaccine against heartwater (based on whole bacteria inactivated with sodium azide) is prepared immediately before injection, using a syringe-extrusion method with Montanide ISA50. This is a fastidious time-consuming process and it limits the number of vaccine doses available. To overcome these issues, we tested three different techniques (syringe, vortex and homogenizer) and three Montanide ISA adjuvants (50, 70 and 70M). High-speed homogenizer was the optimal method to emulsify ER antigens with both ISA70 and 70M adjuvants. The emulsions displayed a good homogeneity (particle size below 1 μm and low phase separation), conductivity below 10 μS/cm and low antigen degradation at 4 °C for up to 1 year. The efficacy of the different formulations was then evaluated during vaccination trials on goats. The inactivated ER antigens emulsified with ISA70 and ISA70M in a homogenizer resulted in 80% and 100% survival rates, respectively. A cold-chain rupture assay using ISA70M+ER was performed to mimic possible field conditions exposing the vaccine at 37 °C for 4 days before delivery. Surprisingly, the animal survival rate was still high (80%). We also observed that the MAP-1B antibody response was very similar between animals vaccinated with ISA70+ER and ISA70M+ER emulsions, suggesting a more homogenous antigen distribution and presentation in these emulsions. Our work demonstrated that the combination of ISA70 or ISA70M and homogenizer is optimal for the production of an effective ready-to-use inactivated vaccine against heartwater, which could easily be produced on an industrial scale.     

Virus-like particle vaccines for poliovirus types 1, 2, and 3 with enhanced thermostability expressed in insect cells

Poliovirus (PV) is a pathogen that causes poliomyelitis, which may lead to paralysis and fatality. Inactivated PV vaccines (IPVs) and live-attenuated oral PV vaccines (OPVs) are currently used to defend against PV worldwide. Vaccines must be developed in a PV-free environment given the biosafety issues associated with OPV and IPV production and to eradicate PV globally. In this study, PV1, PV2, and PV3 virus-like particles with enhanced thermostability (PV-sVLPs) were produced in large quantities by using a baculovirus expression vector system (BEVS). Mice immunized with PV-sVLPs generated antibodies with strong PV-neutralizing response. In addition, splenocytes collected from immunized mice expressed high levels of IFN-γ, IL-2, GM-CSF, IL-5, and IL-10 upon PV-sVLPs stimulation. These data suggest that PV-sVLPs can serve as vaccines against PV infection.