禽流感新型疫苗研究进展

禽流感是由A型流感病毒引起的一种急性呼吸道传染病,家禽、野鸟和部分哺乳动物均可感染.禽流感给中国养殖业造成了巨大的损失,同时,随着病毒的种间传播,人类的生命安全也受到了严重威胁.目前,疫苗免疫仍是防控禽流感最主要的手段,传统的疫苗主要有鸡胚灭活苗和禽流感弱毒疫苗.虽然在过往几次禽流感暴发过程中,传统疫苗发挥了重要作用,但其自身却存在诸多弊端,因此研制新型疫苗来弥补传统疫苗的不足是很有必要的.文章主要对禽流感重组活载体疫苗、基因工程亚单位疫苗、DNA疫苗和病毒样颗粒疫苗等新型疫苗的研究进展进行综述,旨在为禽流感的防控提供参考.     

禽流感DNA疫苗研究进展

禽流感（avian influenza,AI）是由禽流感病毒（AIV）引起的一种禽类烈性综合征,威胁动物和人类公共健康,严重影响中国养禽业发展,接种疫苗一直是控制禽流感病毒传播最有效的手段。基于基因工程技术的不断发展,各种新型疫苗相继研发并投入使用。其中,禽流感DNA疫苗具有安全性高、制备方法简单、易于储藏和运输等优点,受到了广泛关注。常见的禽流感疫苗有HA DNA疫苗、NA DNA疫苗、M DNA疫苗、NP DNA疫苗等。禽流感DNA疫苗是将含有目的基因序列的重组质粒导入动物细胞,诱导动物机体产生体液和细胞免疫应答。为了提高禽流感DNA疫苗的免疫效果,国内外学者通过添加合适的佐剂、将目的基因导入理想质粒载体、对抗原序列优化,增强DNA疫苗的转染效率和基因表达水平,取得了一定的研究成果。自DNA疫苗开始研发至今,H1、H3、H5、H7、H9等众多亚型禽流感DNA疫苗逐步研发。2018年,由中国农业科学院哈尔滨兽医研究所研制的禽流感H5亚型DNA疫苗获得国家一类新兽药证书,是中国首个获得批准的禽流感DNA疫苗,极大地推动了DNA疫苗的发展。文章主要论述了禽流感DNA疫苗的载体构建、免疫机制、佐剂和载体选择以及疫苗研发等方面的研究进展和创新,并对其应用前景进行简要分析,旨在为科研工作者研制新型禽流感疫苗提供新的思路和参考。     

Review of DNA Vaccine for Avian Influenza

Avian influenza (AI) is a kind of avian virulent syndrome caused by avian influenza virus (AIV),which threatens animal and human public health and seriously affects the development of poultry industry in China.Vaccination has always been the most effective means to control the spread of avian influenza virus.Based on the continuous development of genetic engineering technology,a variety of new vaccines have been developed and put into use.Among them,avian influenza DNA vaccine has many advantages,such as high safety,simple preparation,easy storage and transportation.Common HA DNA vaccine,NA DNA vaccine,M DNA vaccine,NP DNA vaccine.Avian influenza DNA vaccine introduces a recombinant plasmid containing the target gene sequence into animal cells to induce a humoral and cellular immune response.In order to improve the immune effect of avian influenza DNA vaccine,researchers at home and abroad have made some achievements in enhancing the transfection efficiency and gene expression level of DNA vaccine by adding appropriate adjuvants,introducing target genes into ideal plasmid vectors and optimizing antigen sequence.Since the development of DNA vaccines,many subtypes of avian influenza DNA vaccines,including H1,H3,H5,H7 and H9 subtypes,have been gradually developed.In 2018,the H5 subtype DNA vaccine developed by Harbin Veterinary Research Institute of The Chinese Academy of Agricultural Sciences obtained the National Class Ⅰ Veterinary Medicine certificate,which is the first DNA vaccine of avian influenza to be approved in China,greatly promoting the development of DNA vaccines.This review mainly discusses the development and innovation of avian influenza DNA vaccine in terms of vector construction,immune mechanism,adjuvant and vector selection,and vaccine research and development,and briefly analyzes its application prospect,in order to provide new ideas and references for researchers to develop new avian influenza vaccine.     

抗禽流感病毒药物和疫苗的研究进展

禽流感对养禽业造成严重危害的同时,还威胁着人类的健康。作者对国内外禽流感近年来的流行现状、禽流感病毒的作用机制、疫苗控制和抗禽流感的药物治疗进行了综述。     

禽流感疫苗的研究进展

禽流感是一种可以引起禽类感染的疾病的综合征,对养禽业造成了巨大的经济损失,同时还具有重要的公共卫生学意义。文中就预防禽流感的多种疫苗,主要以传统和新型两大类别疫苗为主进行简要综述,旨在为禽流感的科学防控提供参考。     

禽流感疫苗研究进展

近几年禽流感的大范围流行,不仅给养禽业造成了巨大的经济损失,而且由于禽流感可直接感染人并导致死亡,故对人类健康也带来严重的威胁。疫苗免疫仍然是防止禽流感暴发的主要措施,但禽流感病毒变异性强,血清型众多,给疫苗的研究带来极大困难。就目前而言,能在实践上应用的禽流感疫苗主要还是灭活疫苗,这种疫苗具有亚型特异性,但也正是这种特性限制了这种疫苗的发展。随着生物技术的快速发展,其他新型疫苗尤其是基因工程疫苗的研究也取得了一定的进展。使我国应用禽流感疫苗,预防高致病力禽流感的防制策略成为可能。文章就目前禽流感疫苗的研究方面介绍了国内外的一些研究进展。     

禽流感病毒分子生物学检测技术研究进展

禽流感(avian influenza,AI)是A型流感病毒引起的一种禽类传染病,同时也是一种人和动物之间的高度传染性疾病。近年来,禽流感病毒的分子生物学检测技术发展迅速,文章就此进行了综述。     

H9N2亚型禽流感病毒疫苗研究进展

H9N2亚型禽流感病毒在世界范围内广泛存在,给养禽业造成巨大的经济损失,并危害人类健康。流感病毒抗原易发生漂移和转换,使流感病毒的防控变得困难。疫苗接种是防控禽流感最有效的手段之一,全病毒灭活疫苗保护效果好,制备简单,是流感病毒常用的疫苗,但该疫苗局部副反应大,并伴随生物安全问题。随着分子生物学技术的发展,活载体疫苗、核酸疫苗、亚单位疫苗等新型疫苗的开发,给H9N2亚型禽流感病毒的防控提供了新的手段。新型疫苗除具有传统疫苗的保护效果外,在生物安全和普遍防控方面具有广泛的优势,是流感病毒疫苗发展的新方向。     

禽流感防制进展

禽流感（Avian influenza,AI）是由A型流感病毒所引起的禽类的一种传染病。能引起禽类呼吸系统到严重全身败血症等多种症状的烈性传染病。禽类感染后病死率很高,但对野生禽类多为不显性感染。自从1997年香港发生禽流感病毒H5N1亚型首次突破种属屏障感染人类并引起死亡以来,世界各国纷纷报道各种人禽流感病例的发生,人禽流感的关注程度也达到了前所未有的高度。近几年全球共有三大洲的19个国家和地区发生禽流感疫情。一些地区的疫情呈现蔓延的趋势,并且出现了人感染禽流感病毒的病例。禽流感不仅对养殖业造成重大损失,更对人类健康造成严重威胁。本文全面地介绍了禽流感的病原、流行病学、临床症状、病理变化、诊断和防制。     

禽流感病毒分子生物学的研究进展

禽流行性感冒(av ian in fluenza,A I,简称禽流感)是由A型禽流感病毒(av ian in fluenza v irus,A IV)引起的禽类烈性传染病。作为被世界动物卫生组织(O IE)定为A类的传染病,A I不仅给世界养禽业造成了巨大的经济损失,而且对人类健康和生命安全构成了严重威胁。因此,A I已经成为人们关注的焦点,国内外学者也对其进行了大量研究。作者从病原基因组及其编码的蛋白质、致病力、变异性以及对人类感染A IV的分子机制等角度就A IV的分子生物学研究作一综述,为防制A I提供理论基础,并在此基础上探讨了人类禽流感的防治措施,加深人们对A I的认识。     

Avian influenza vaccines and therapies for poultry

Vaccines have been used in avian influenza (AI) control programs to prevent, manage or eradicate AI from poultry and other birds. The best protection is produced from the humoral response against the hemagglutinin (HA) protein. A variety of vaccines have been developed and tested under experimental conditions with a few receiving licensure and field use following demonstration of purity, safety, efficacy and potency. Current licensed vaccines are predominately inactivated whole AI vaccines, typically produced from low pathogenicity (LP) AI virus strains, or occasionally from high pathogenicity AI virus strains. Recently, reverse genetic procedures have been developed that allow construction of vaccine strains using a genetically altered HA gene (changing HP HA proteolytic cleavage site to LP) and a backbone of internal gene segments for safe, high growth production. Other licensed AI vaccines include recombinant fowl poxvirus vector with an AI H5 insert and a recombinant Newcastle disease virus vector with an AI H5 gene insert. The latter vaccine can be mass administered via aerosol application.     

Influenza vaccines and vaccination strategies in birds

Although it is well accepted that the present Asian H5N1 panzootic is predominantly an animal health problem, the human health implications and the risk of human pandemic have highlighted the need for more information and collaboration in the field of veterinary and human health. H5 and H7 avian influenza (AI) viruses have the unique property of becoming highly pathogenic (HPAI) during circulation in poultry. Therefore, the final objective of poultry vaccination against AI must be eradication of the virus and the disease. Actually, important differences exist in the control of avian and human influenza viruses. Firstly, unlike human vaccines that must be adapted to the circulating strain to provide adequate protection, avian influenza vaccination provides broader protection against HPAI viruses. Secondly, although clinical protection is the primary goal of human vaccines, poultry vaccination must also stop transmission to achieve efficient control of the disease. This paper addresses these differences by reviewing the current and future influenza vaccines and vaccination strategies in birds.     

Vaccines protect chickens against H5 highly pathogenic avian influenza in the face of genetic changes in field viruses over multiple years

Inactivated whole avian influenza (AI) virus vaccines, baculovirus-derived AI haemagglutinin vaccine and recombinant fowlpoxvirus-AI haemagglutinin vaccine were tested for the ability to protect chickens against multiple highly pathogenic (HP) H5 AI viruses. The vaccine and challenge viruses, or their haemagglutinin protein components, were obtained from field AI viruses of diverse backgrounds and included strains obtained from four continents, six host species, and isolated over a 38-year-period. The vaccines protected against clinical signs and death, and reduced the number of chickens shedding virus and the titre of the virus shed following a HP H5 AI virus challenge. Immunization with these vaccines should decrease AI virus shedding from the respiratory and digestive tracts of AI virus exposed chickens and reduce bird-to-bird transmission. Although most consistent reduction in respiratory shedding was afforded when vaccine was more similar to the challenge virus, the genetic drift of avian influenza virus did not interfere with general protection as has been reported for human influenza viruses.     

Recent developments in avian influenza research: epidemiology and immunoprophylaxis

Influenza A viruses have been isolated from humans, from several other mammalian species and a wide variety of avian species, among which, wild aquatic birds represent the natural hosts of influenza viruses. The majority of the possible combinations of the 15 haemagglutinin (HA) and nine neuraminidase (NA) subtypes recognized have been identified in isolates from domestic and wild birds. Infection of birds can cause a wide range of clinical signs, which may vary according to the host, the virus strain, the host's immune status, the presence of any secondary exacerbating microorganisms and environmental factors. Most infections are inapparent, especially in waterfowl and other wild birds. In contrast, infections caused by viruses of H5 and H7 subtypes can be responsible for devastating epidemics in poultry. Despite the warnings to the poultry industry about these viruses, in 1997 an avian H5N1 influenza virus was directly transmitted from birds to humans in Hong Kong and resulted in 18 confirmed infections, thus strengthening the pandemic threat posed by avian influenza (AI). Indeed, reassortant viruses, harbouring a combination of avian and human viral genomes, have been responsible for major pandemics of human influenza. These considerations warrant the need to continue and broaden efforts in the surveillance of AI. Control programmes have varied from no intervention, as in the case of the occurrence of low pathogenic (LP) AI (LPAI) viruses, to extreme, expensive total quarantine-slaughter programmes carried out to eradicate highly pathogenic (HP) AI (HPAI) viruses. The adoption of a vaccination policy, targeted either to control or to prevent infection in poultry, is generally banned or discouraged. Nevertheless, the need to boost eradication efforts in order to limit further spread of infection and avoid heavy economic losses, and advances in modern vaccine technologies, have prompted a re-evaluation of the potential use of vaccination in poultry as an additional tool in comprehensive disease control strategies. This review presents a synthesis of the most recent research on AI that has contributed to a better understanding of the ecology of the virus and to the development of safe and efficacious vaccines for poultry.     

禽大肠杆菌病疫苗研究进展

禽致病性大肠杆菌(APEC)是引起家禽多种肠外疾病如气囊炎、心包炎、肝周炎、蜂窝织炎及败血症的主要人畜共患病原菌.在过去的数十年间,试验了多种不同类型的疫苗用于本病的控制.鉴于APEC血清型较多且不同血清型之间缺乏交叉免疫保护,故生产上使用的APEC疫苗研究进展缓慢.作者对不同类型APEC疫苗进行了综述并提出未来的研究方向.     

Improvements to the hemagglutination inhibition test for serological assessment of recombinant fowlpox-H5-avian-influenza vaccination in chickens and its use along with an agar gel immunodiffusion test for differentiating infected from noninfected vaccinated animals

In general, avian influenza (AI) vaccines protect chickens from morbidity and mortality and reduce, but do not completely prevent, replication of wild AI viruses in the respiratory and intestinal tracts of vaccinated chickens. Therefore, surveillance programs based on serological testing must be developed to differentiate vaccinated flocks infected with wild strains of AI virus from noninfected vaccinated flocks in order to evaluate the success of vaccination in a control program and allow continuation of national and international commerce of poultry and poultry products. In this study, chickens were immunized with a commercial recombinant fowlpox virus vaccine containing an H5 hemagglutinin gene from A/turkey/Ireland/83 (H5N8) avian influenza (AI) virus (rFP-H5) and evaluated for correlation of immunological response by hemagglutination inhibition (HI) or agar gel immunodiffusion (AGID) tests and determination of protection following challenge with a high pathogenicity AI (HPAI) virus. In two different trials, chickens immunized with the rFP-H5 vaccine did not develop AGID antibodies because the vaccine lacks AI nucleoprotein and matrix genes, but 0%-100% had HI antibodies, depending on the AI virus strain used in the HI test, the HI antigen inactivation procedure, and whether the birds had been preimmunized against fowlpox virus. The most consistent and highest HI titers were observed when using A/turkey/Ireland/83 (H5N8) HPAI virus strain as the beta-propiolactone (BPL)-inactivated HI test antigen, which matched the hemagglutinin gene insert in the rFP-H5 vaccine. In addition, higher HI titers were observed if ether or a combination of ether and BPL-inactivated virus was used in place of the BPL-inactivated virus. The rFP-H5 vaccinated chickens survived HPAI challenge and antibodies were detected by both AGID and HI tests. In conclusion, we demonstrated that the rFP-H5 vaccine allowed easy serological differentiation of infected from noninfected birds in vaccinated populations of chickens when using standard AGID and HI tests.     

禽流感病毒的致病性和免疫性研究进展

介绍了禽流感病毒的病原、基因结构及其对禽类、人类的致病机理和危害，探讨了感染病毒后宿主的反应、机体的体液免疫和细胞免疫，在一定程度上概述了禽流感病毒的固有特点和规律，为进一步研究打下了基础。     

禽流感诊断技术研究进展

禽流感是严重危害畜牧业和人类健康的一种传染性疾病,多年来在世界上许多国家和地区都发生过此病,危害巨大.世界各国对其进行了大量研究.文章就目前国内外对禽流感病毒血清学和分子生物学诊断技术的研究进展做一综述.     

猪流感疫苗研究进展

全面综述了国内外猪流感（SI）疫苗的研究现状。从激发体液免疫、细胞免疫、交叉保护以及避免母源抗体干扰和区分野毒感染等方面分别阐述了常规疫苗、减毒疫苗、亚单位疫苗、DNA疫苗、病毒活载体疫苗的研究进展,以期找到最佳控制猪流感的疫苗及免疫方案,为进一步研究猪流感疫苗提供参考。