China
Africa
Explore chapters and articles related to this topic
The Immunological System and Neoplasia
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
The first vaccine was developed and marketed in 1982 using HBsAg as the immunogen. The HBsAg was derived from blood plasma obtained from infected individuals. Since 1986 recombinant vaccines have been introduced, in which HBsAg is produced by Saccharomyces cerevisiae (also known as baker′s yeast) containing the gene for HBsAg. Thus far this is the only example of a recombinant vaccine commercially available for use in humans. Currently over eighty countries have implemented vaccination programs resulting not only in protection in vaccinated children but also in reducing the overall rate of infection in nonvaccinated groups. If the mother is HBsAg positive, the vaccine needs to be given within twelve hours of birth in combination with high-titered HBV-specific immunoglobulin to achieve protection. The protection given by the vaccine is based on the development of antibodies against HBsAg. The antibodies neutralize HBV particles. The vaccine is similar to other inactivated antiviral vaccines. The vaccine-induced protection against HCC is solely based on protection against virus infection.
Marvellous molecules
Published in Brendan Curran, A Terrible Beauty is Born, 2020
The first choice was the simple yeast cell because not only does it have primitive versions of all the major cellular compartments of human cells, but it also has many of the characteristics that made bacteria the choice for the original cloning system. Yeast grows rapidly as single cells, forms colonies on plates and has a plasmid, so allowing it to be genetically engineered more easily than complex organisms. Furthermore, yeast has a long history of safe use in the brewing industry. The first commercially successful recombinant vaccine was produced in yeast after E. coli was found to be unable to fold it properly. Before the advent of genetic engineering, the hepatitis B vaccine had been prepared by purifying the relevant protein from the blood of individuals who were suffering from the disease – a worrying thought when one considers that many patients who have the hepatitis B virus have also acquired the AIDS virus. Recombinant DNA technology enabled scientists to clone the viral gene encoding this protein, splice it into the regulatory sequence from a yeast gene and make the viral protein in yeast. Thanks to gene expression technology, a jab in the doctor’s surgery is now much safer.
Protein Subunit Vaccines and Recombinant DNA Technology
Published in F. Y. Liew, Vaccination Strategies of Tropical Diseases, 2017
The purpose of this chapter is essentially twofold. First, the present state of available methodology is reviewed. Although recombinant DNA technology is becoming well established as a number of individual techniques, the molecular biologist is still left with a large number of scientific and technical problems before serious academic or commercial considerations as to the most appropriate system to be used can be made. That the considerable resource required to bring such products to the market is worthwhile is evidenced by the fact that a very large number of biotechnology companies are researching recombinant vaccine technology. In subsequent sections the basic techniques and the options available for utilizing recombinant DNA technology will be discussed. Clearly an article of this type cannot be exhaustive, but it is hoped that the essence of the field will be given. Relevant references will be provided as appropriate. Second, an overview of subunit vaccines is provided. This includes the range of organisms and the proteins involved, the problems associated with their production, and their potential effectiveness as vaccines.
Research progress on substitution of in vivo method(s) by in vitro method(s) for human vaccine potency assays
Published in Expert Review of Vaccines, 2023
Xuanxuan Zhang, Xing Wu, Qian He, Junzhi Wang, Qunying Mao, Zhenglun Liang, Miao Xu
Potency is ‘The measure of the biological activity using a suitably quantitative biological assay, based on the attribute of the product which is linked to the relevant biological properties’ [4,5]. The potency of a final lot, which is directly associated with its efficacy, is a critical quality attribute (CQA) for vaccine quality control and release [6]. Typically, vaccine potency assays include in vivo and in vitro methods. In vivo assays require the assessment of protection against a challenge or antibody detection after immunization of animals. In vitro assays generally require the determination of the vaccine immunogen content. Vaccine potency assays are selected depending on vaccine types. In general, the in vitro virus titration method or bacterial content determination is employed for attenuated live vaccines; in vivo assays are adopted for assessing inactivated vaccines; the contents of major immunogenic components are determined for subunit vaccines; in vitro or in vivo assays are utilized for nucleic acid or viral vector vaccines [7–10]. During the initial stage of recombinant vaccine, in vivo assays are used, while confirming the correlation between in vitro and in vivo assays, in vivo assays can be substituted by in vitro assays.
Effects of information sources in HPV vaccine acceptance: prospective randomized trial
Published in Postgraduate Medicine, 2022
Human papillomaviruses (HPV) are among the most common sexually transmitted viral disease. Persistent HPV infection and anogenital warts may be precursors for gynecological, anal, and oropharyngeal cancers. Therefore, HPV vaccine has proven beneficial effect on anogenital warts and anogenital intraepithelial neoplasia. The HPV vaccine has been used in many countries since the 2000s. According to the Centers for Disease Control and Prevention Agency, four out of every five sexually active women are exposed to HPV infection once in their lifetime [1]. Previous studies have revealed a close relation between persistent HPV infection and oropharyngeal cancers, anal dysplasia, anogenital warts, and gynecologic cancers [2]. To prevent HPV-related complications, HPV quadrivalent (types 6, 11, 16, and 18) recombinant vaccine was approved due to its proven beneficial effect on cervical warts, cervical cancer, cervical intraepithelial neoplasia, vulvar and vaginal neoplasms. Recently, the HPV vaccine was recommended for routine vaccination at age 11 or 12 years and for all those up to 26 years if not adequately vaccinated previously [3]. However, there are many factors in individuals’ acceptance of the vaccine, including education level, race, religion, knowledge of HPV, and source of information about HPV [4,5].
Autoantibody of interleukin-17A induced by recombinant Mycobacterium smegmatis attenuates airway inflammation in mice with neutrophilic asthma
Published in Journal of Asthma, 2022
Ling Chen, Wanting Xu, Song Mao, Ruochen Zhu, Jianhua Zhang
Currently, a variety of monoclonal antibodies (mAb) and soluble receptors have been developed to neutralize the over-produced endogenous cytokines associated with severe disease. It has been reported that administration of monoclonal antibody or soluble receptor to block over-produced IL-13 has been proven to be effective in controlling airway inflammation in a murine model of asthma (32). However, these approaches have disadvantages of high costs, frequent injections, short half-lives, and possible adverse effects (33,34). In order to overcome these disadvantages mentioned above, a new strategy that may offer long-term efficacy with fewer adverse effects has emerged. According to previous studies, a recombinant vaccine was prepared by inserting a peptide derived from the immunodominant epitope region of the targeted self-cytokine into the immunodominant epitope region of the carrier using gene recombination method to induce specific autoantibody (35,36). Based on the above theory, a recombinant Mycobacterium smegmatis-inducing IL-17A autoantibody was designed in our previous work (21), experimental results have shown that the recombinant Mycobacterium smegmatis had a long-term efficacy of generating IL-17A autoantibody after immunization with rMS, more importantly, these autoantibodies had high activity to neutralize IL-17A.