狂犬病病毒Vero细胞适应株的建立及其应用于疫苗生产的可行性探讨

将狂犬病病毒７ａＧ固定毒适应于Ｖｅｒｏ细胞,建立了稳定的ＶＲＧ适应株。病毒滴度可达７．６９ｌｏｇＬＤ５０／ｍｌ,病毒最适增殖时间５—７天,最适种毒比例１：１０￣３。应用转瓶培养Ｖｅｒｏ细胞增殖病毒,收获病毒液经β—丙内脂灭活,超离浓缩制备疫苗,效力试验结果（ＮＩＨ法）较原制疫苗成倍增高,且都大于２．５ＩＵ／２ｍｌ,表明ＶＲＧ适应株可应用于制备Ｖｅｒｏ细胞狂犬病疫苗。     

人用精制Vero细胞狂犬病疫苗的保护性试验

用ＣＴＮ－１Ｖ株生产的精制Ｖｅｒｏ细胞狂犬病疫苗腹腔免疫小鼠后,再用狂犬病毒街毒株ＳＢＤ０７脑内和肌肉攻击,结果表明稀释５倍疫苗的保护率分别为８８．９％和９０％,且５倍稀释疫苗的保护效果与原苗相当,此研究证明ＣＴＮ－１Ｖ株能用来作为疫苗的生产毒株。     

用Vero细胞大量制备传染性法氏囊病病毒

目前传染性法氏囊病病毒疫苗主要是用原代鸡胚成纤维细胞 (ＰＣＥＦ)增殖ＩＢＤＶ进行生产。由于ＳＰＦ种蛋价格高 ,且ＳＰＦ种蛋在取得及培养过程中易被外源病原污染 ,造成产品质量的不稳定 ,生产成本很高[1] 。Ｖｅｒｏ细胞系是一种贴壁依赖性的传代细胞系 ,ＷＨＯ已经批准用Ｖｅｒｏ细胞作为载体进行病毒疫苗的生产。目前已成功地应用Ｖｅｒｏ细胞生产出脊髓灰质炎病毒疫苗和狂犬病毒疫苗[2 ] 。用Ｖｅｒｏ细胞生产传染性法氏囊病病毒疫苗也会有较好的前景。我们已完成了在Ｖｅｒｏ细胞上静止状态下增殖ＩＢＤＶ弱毒株的培养条件研究 ,而…     

Vero细胞狂犬疫苗研究和生产进展

自ＷＨＯ推荐Ｖｅｒｏ细胞用于疫苗生产后,国内外相继进行以Ｖｅｒｏ细胞为基质的人用狂犬疫苗的研究和应用,Ｖｅｒｏ细胞以繁殖快,质量可高效控制,不污染外源因子,对不同毒株有广泛的适应性,且可在细胞反应器中进行工业化生产,病毒滴度高、成本低、疫苗质量好,有较大的发展前景。     

传染性法氏囊病病毒弱毒株对Vero细胞的适应性研究

传染性法氏囊病病毒疫苗的传统生产工艺是利用鸡胚纤维细胞增殖ＩＢＤＶ,但易被外源病原污染,且生产成本很高,借鉴国内外流行性乙型脑炎疫苗生产的经验,使用Ｖｅｒｏ细胞增殖ＩＢＤＶ弱毒株,从病毒高峰出现时间、滴度峰值的高低、对细胞代谢的影响等方面研究了ＩＢＤＶ对Ｖｅｒｏ细胞的适应性,敏感性以及适应后的种毒的长期保存过程中发现病毒滴度有下降趋势,试用了不同试剂对病毒进行保护。     

浓缩地鼠肾细胞狂犬病疫苗与纯化Vero细胞狂犬病疫苗接种 …

为了解国产浓缩地鼠肾细胞狂犬疫苗与法国纯化Ｖｅｒｏ细胞狂犬疫苗接种人体后中和抗体产生情况。分别用两种疫苗接种１０人,用小鼠中和试验方法检测中和抗体滴度。国产疫苗五针全程免疫后３０天（第一针按种后６０天）可１００％达到保护水平,法国疫苗在第一针接种后３０天１００％达到保护水平。第一针接种后１４、３０、６０天时,前者抗体平均滴度分别是０．０６ＩＵ／ｍｌ、１０２ＩＵ／ｍｌ、２．０７ＩＵ／ｍｌ;后者抗体平     

应用Vero细胞检定法和家兔皮内中和法检测吸附白喉类毒素的效价

Ｖｅｒｏ细胞法测定ＤＴＰ疫苗中白喉类毒素的效价与家兔皮内中和法（简称ＮＴ法）所得结果两法之间有一种平行关系,并且有很好的相关性,ｒ＝０．９３。但Ｖｅｒｏ细胞法测得平均值低于ＮＴ法,二者之间的平均比率为０．２８７,Ｓ＝０．０８９。本试验结果与１９９５部颁规程ＮＴ法０．２５ＩＵ／ｍｌ相比,确定了Ｖｅｒｏ细胞法以０．０７ＩＵ／ｍｌ作为检定吸附ＤＴＰ效价的最低要求。     

人用精制Vero细胞狂犬病疫苗纯化方法选择

人用精制Ｖｅｒｏ细胞狂犬病疫苗为一种安全、有效的新型疫苗,我们在研制该种疫苗时首先比较了密度梯度离心法和凝胶过滤柱层析法,并发现后者最佳。我们选择了以Ｓｅｐｈａｒｏｓｅ ４ＦＦ为介质的凝胶过滤柱层析的工艺,并对该方法的上样量、流速等指标进行了选择,确定了最佳方法,并在研制中使纯化疫苗的杂蛋白去除率达到９９．８％以上,为大规模生产提供了工艺方法。     

大规模区带离心纯化Vero细胞乙脑疫苗

本文报道一种适合疫苗生产的大规模纯化Ｖｅｒｏ细胞乙脑疫苗的方法。原疫苗经适当浓缩和去除ＤＮＡ处理后,用不连续蔗糖梯度（３６％和６０％）。３２６００ｇ,速率区带离心４ｈ。纯化后疫苗的效力比中国参考疫苗高出６倍以上,补体结合抗原比中国参考疫苗高４～８倍。总蛋白含量低于３０μｇ／ｍＬ,牛血清含量降至０．５μｇ／ｍＬ以下,细胞残余ＤＮＡ低于１００ｐｇ／０．５ｍＬ。用此法连续制备三批纯化疫苗,其纯度和效力均高于日本鼠脑纯化疫苗。此法对于制备其它纯化Ｖｅｒｏ细胞疫苗也具有一定的参考意义。     

犬瘟热病毒细胞膜受体的鉴定

犬瘟热病毒（ＣＤＶ）敏感细胞Ｖｅｒｏ用ＳＤＳ或ＲＩＰＡ溶解缓冲液溶解,利用病毒铺覆蛋白印迹技术（ＶＯＰＢＡ）鉴定犬瘟热病毒疫苗株（ＣＤＶ－ｏｎｄｅｓｔｅｐｏｏｒｔ）的细胞受体。结果发现,在Ｖｅｒｏ细胞上有两组ＣＤＶ结合蛋白质,即高分子量组蛋白质（１２７ｋＤ、１２０ｋＤ、１１０ｋＤ）与低分子量组蛋白质（２７ｋＤ和３０ｋＤ）。这些ＣＤＶ结合蛋白组分的性质及在ＣＤＶ致病中的作用有等进一步研究。     

Safety of the malaria vaccine candidate, RTS,S/AS01E in 5 to 17 month old Kenyan and Tanzanian Children

The malaria vaccine candidate, RTS,S/AS01(E), showed promising protective efficacy in a trial of Kenyan and Tanzanian children aged 5 to 17 months. Here we report on the vaccine's safety and tolerability. The experimental design was a Phase 2b, two-centre, double-blind (observer- and participant-blind), randomised (1∶1 ratio) controlled trial. Three doses of study or control (rabies) vaccines were administered intramuscularly at 1 month intervals. Solicited adverse events (AEs) were collected for 7 days after each vaccination. There was surveillance and reporting for unsolicited adverse events for 30 days after each vaccination. Serious adverse events (SAEs) were recorded throughout the study period which lasted for 14 months after dose 1 in Korogwe, Tanzania and an average of 18 months post-dose 1 in Kilifi, Kenya. Blood samples for safety monitoring of haematological, renal and hepatic functions were taken at baseline, 3, 10 and 14 months after dose 1. A total of 894 children received RTS,S/AS01(E) or rabies vaccine between March and August 2007. Overall, children vaccinated with RTS,S/AS01(E) had fewer SAEs (51/447) than children in the control group (88/447). One SAE episode in a RTS,S/AS01(E) recipient and nine episodes among eight rabies vaccine recipients met the criteria for severe malaria. Unsolicited AEs were reported in 78% of subjects in the RTS,S/AS01(E) group and 74% of subjects in the rabies vaccine group. In both vaccine groups, gastroenteritis and pneumonia were the most frequently reported unsolicited AE. Fever was the most frequently observed solicited AE and was recorded after 11% of RTS,S/AS01(E) doses compared to 31% of doses of rabies vaccine. The candidate vaccine RTS,S/AS01(E) showed an acceptable safety profile in children living in a malaria-endemic area in East Africa. More data on the safety of RTS,S/AS01(E) will become available from the Phase 3 programme.     

A simple immuno-capture ELISA to estimate rabies viral glycoprotein antigen in vaccine manufacture.

Rabies is an endemic, fatal zoonotic disease in the developing countries. Prevention and post-exposure therapy require safe and efficacious vaccines. The vaccine potency depends on the amount of immunogenic rabies viral glycoprotein antigen in the vaccine preparation. In order to estimate the rabies viral glycoprotein antigen, a specific monoclonal antibody was developed and used in an immuno-capture ELISA (IC-ELISA). The monoclonal antibody binds a conformational epitope on the natively folded rabies viral glycoprotein as indicated by specific, membrane fluorescence on unfixed, rabies virus infected murine neuroblastoma (MNA) cells and glycoprotein gene encoding plasmid transfected COS cells. In addition, the monoclonal antibody competes with and blocks a glycoprotein antigen site III binding monoclonal antibody (mAb-D1, Institut Pasteur, Paris, France). The monoclonal antibody was used in an IC-ELISA using an in-house standard to quantify the rabies viral glycoprotein antigen in 12 vaccine preparations with potency values ranging from 4 to 18 IU. The results indicated a good correlation with the NIH mouse potency assay (r=0.83). The immuno-capture ELISA described in this study can be used to quantify the immunogenic rabies viral glycoprotein antigen in the inactivated rabies viral antigen preparation in a simple and rapid format, which enables better vaccine formulation.     

The use of an E1-deleted, replication-defective adenovirus recombinant expressing the rabies virus glycoprotein for early vaccination of mice against rabies virus.

An E1-deleted, replication-defective adenovirus recombinant of the human strain 5 expressing the rabies virus glycoprotein, termed Adrab.gp, was tested in young mice. Mice immunized at birth with the Adrab.gp construct developed antibodies to rabies virus and cytokine-secreting lymphocytes and were protected against subsequent challenge. Maternal immunity to rabies virus strongly interferes with vaccination of the offspring with a traditional inactivated rabies virus vaccine. The immune response to the rabies virus glycoprotein, as presented by the Adrab.gp vaccine, on the other hand, was not impaired by maternal immunity. Even neonatal immunization of mice born to rabies virus-immune dams with Adrab.gp construct resulted in a long-lasting protective immune response to rabies virus, suggesting that this type of vaccine could be useful for immunization shortly after birth. Nevertheless, pups born to Adrab.gp virus-immune dams showed an impaired immune response to the rabies virus glycoprotein upon vaccination with the Adrab.gp virus, indicating that maternal immunity to the vaccine carrier affected the offspring's immune response to rabies virus.     

Evaluation of rabies virus neutralizing antibody titres induced by intramuscular inoculation of rabies DNA vaccine in mice and Bonnet monkeys (Macaca radiata)

A rabies DNA vaccine consisting of plasmid DNA expressing the rabies virus surface glycoprotein was injected (im) twice at two week interval to outbred swiss mice or Bonnet monkeys (Macaca radiata) and the levels of rabies virus neutralizing antibody (VNA) titres were examined over a one year period. In mice, the VNA titre was maintained above the minimum protective level (0.5 I.U./ml) up to 10 months after primary immunization, while in monkeys, the titre dropped below the protective level by 6 months. An anamnestic B cell response was seen in both mice and monkeys following the administration of a booster dose, 10 and 6 months after the primary immunization, respectively. These results indicate that im injection of rabies DNA vaccine induces VNA in nonhuman primates and mice unlike intradermal (id) immunization, which was shown to induce VNA only in mice but not in monkeys. This is the first report on the induction of VNA in nonhuman primates by im inoculation of rabies DNA vaccine.     

Newcastle disease virus-vectored rabies vaccine is safe, highly immunogenic, and provides long-lasting protection in dogs and cats

Effective, safe, and affordable rabies vaccines are still being sought. Newcastle disease virus (NDV), an avian paramyxovirus, has shown promise as a vaccine vector for mammals. Here, we generated a recombinant avirulent NDV La Sota strain expressing the rabies virus glycoprotein (RVG) and evaluated its potential to serve as a vaccine against rabies. The recombinant virus, rL-RVG, retained its high-growth property in chicken eggs, with titers of up to 10^9.8 50% egg infective doses (EID₅₀)/ml of allantoic fluid. RVG expression enabled rL-RVG to spread from cell to cell in a rabies virus-like manner, and RVG was incorporated on the surface of the rL-RVG viral particle. RVG incorporation did not alter the trypsin-dependent infectivity of the NDV vector in mammalian cells. rL-RVG and La Sota NDV showed similar levels of sensitivity to a neutralization antibody against NDV and similar levels of resistance to a neutralization antibody against rabies virus. Animal studies demonstrated that rL-RVG is safe in several species, including cats and dogs, when administered as multiple high doses of recombinant vaccine. Intramuscular vaccination with rL-RVG induced a substantial rabies virus neutralization antibody response and provided complete protection from challenge with circulating rabies virus strains. Most importantly, rL-RVG induced strong and long-lasting protective neutralization antibody responses to rabies virus in dogs and cats. A low vaccine dose of 10^8.3 EID₅₀ completely protected dogs from challenge with a circulating strain of rabies virus for more than a year. This is the first study to demonstrate that immunization with an NDV-vectored vaccine can induce long-lasting, systemic protective immunity against rabies.     

精制Vero细胞狂犬病疫苗的灭活和纯化

通过狂犬病病毒灭活和纯化试验,试验精制Vero细胞狂犬病疫苗。疫苗经检测残余小牛血清白蛋白含量,Vero细胞残余DNA含量,疫苗效价,安全试验均能达到WHO规程要求。初步建立了适合大规模生产精制Vero细胞狂犬病疫苗的灭活和纯化工艺。     

精制地鼠肾细胞狂犬病疫苗纯化工艺的建立

分别用Srpharose4B、Sephacryl-200HR和Sepharose6-Fastflow柱色谱进行地鼠肾细胞狂犬病疫苗浓缩原液纯化试验,试制精制地鼠肾细胞狂犬病疫苗.对疫苗的残余牛血清含量、效力、收获率和安全性进行检测,优化和建立了精制地鼠肾细胞狂犬病疫苗纯化工艺.     

Removing residual DNA from Vero-cell culture-derived human rabies vaccine by using nuclease

The clearance of host cell DNA is a critical indicator for Vero-cell culture-derived rabies vaccine. In this study, we evaluated the clearance of DNA in Vero-cell culture-derived rabies vaccine by purification process utilizing ultrafiltration, nuclease digestion, and gel filtration chromatography. The results showed that the bioprocess of using nuclease decreased residual DNA. Dot-blot hybridization analysis showed that the residual host cell DNA was <100 pg/ml in the final product. The residual nuclease in rabies vaccine was less than 0.1 ng/ml protein. The residual nuclease could not paly the biologically active role of digestion of DNA. Experiments of stability showed that the freeze-drying rabies virus vaccine was stable and titers were >5.0 IU/ml. Immunogenicity test and protection experiments indicated mice were greatly induced generation of neutralizing antibodies and invoked protective effects immunized with intraperitoneal injections of the rabies vaccine. These results demonstrated that the residual DNA was removed from virus particles and nuclease was removed by gel filtration chromatography. The date indicated that technology was an efficient method to produce rabies vaccine for human use by using nuclease.     

用CaG株毒种制备精制狂犬病疫苗的研究

通过对狂犬病毒aG株在金黄地鼠肾细胞上传代培养,获得一种新型狂犬病毒毒株,即地鼠肾细胞适应株(CaG株)[1].由于该毒种具有生产方法简单,成本低廉,且外源因子污染机率小等优点,因此试用该毒种生产精制狂犬病疫苗.在相同条件下,分别用豚鼠脑毒种和细胞毒种各生产3批病毒原液,经相同纯化工艺制备成精制狂犬病疫苗.经初步检定用细胞毒种制备的疫苗安全性良好,疫苗免疫效价与豚鼠脑毒种疫苗无明显差异.     

Immunogenicity of multi-epitope-based vaccine candidates administered with the adjuvant Gp96 against rabies

Rabies, a zoonotic disease, causes 55,000 human deaths globally and results in at least 500 million dollars in losses every year. The currently available rabies vaccines are mainly inactivated and attenuated vaccines, which have been linked with clinical diseases in animals. Thus, a rabies vaccine with high safety and efficacy is urgently needed. Peptide vaccines are known for their low cost, simple production procedures and high safety. Therefore, in this study, we examined the efficacy of multi-epitope-based vaccine candidates against rabies virus. The ability of various peptides to induce epitope-specific responses was examined, and the two peptides that possessed the highest antigenicity and conservation, i.e., AR16 and h PAB, were coated with adjuvant canineGp96 and used to prepare vaccines. The peptides were prepared as an emulsion of oil in water(O/W) to create three batches of bivalent vaccine products. The vaccine candidates possessed high safety. Virus neutralizing antibodies were detected on the day 14 after the first immunization in mice and beagles, reaching 5–6 IU/m L in mice and 7–9 IU/m L in beagles by day 28. The protective efficacy of the vaccine candidates was about 70%–80% in mice challenged by a virulent strain of rabies virus. Thus, a novel multi-epitope-based rabies vaccine with Gp96 as an adjuvant was developed and validated in mice and dogs. Our results suggest that synthetic peptides hold promise for the development of novel vaccines against rabies.