兽用生物制品的运输、贮存与使用

对兽用生物制品的命名作了概述,并对免疫预防用制品、诊断用制品、治疗用制品的运输、贮存与使用分别进行了阐述,同时对改善我国兽用生物制品的监管提出了建议。     

Isolation and Identification of a Variant Porcine Epidemic Diarrhea Virus and the Immune Efficacy of Its Inactivated Vaccine

This study was aimed to isolate a mutant strain of porcine epidemic diarrhea virus and prepare a PEDV inactivated vaccine with high valence by suspension culture process for immunizing against PEDV effectively in China.200 small intestines and theirs contents of diarrhea piglets died of diarrhea,collected from many large-scale pig farms in China,were detected by RT-PCR and sequenced,a mutant strain of porcine epidemic diarrhea virus was selected and put on the suspension-cultured Vero cells in a 2 L reactor for virus isolation and continuous cell culture,the harvested virus suspension,which was identified and determined TCID₅₀,was inactivated by formaldehyde and mixed with aluminum hydroxide gel adjuvant to prepare PEDV inactivated vaccine.After its physical behavior,stability viscosity,sterility test were checked out,the safety and immune efficacy were studied by immunizing the pregnant pigs and theirs piglets.The results were as follows:86 samples were detected positive in 200 samples,cytopathy occurred after the mutant strain samples screened were passaged to 5th generation,the virus suspension was harvested in 10th generation and identified as a mutant strain of PEDV,named PEDV-GF10 strain.The virus titer of harvested virus suspension was measured up to 1×10^8.0 TCID₅₀/mL after concentrated.After the vaccine was checked out,the sows,40 and 25 days before delivery in experimental groups,were injected into Xuehai acupoint with 4 mL vaccine and the pigs in blank group were free of immunifications.The results showed that there were no obvious differences in the production status of the sows in experimental groups and blank group and the temperature of theirs 3-day-old healthy piglets injected different doses of vaccine,and the vaccine was safe to the sows and piglets.Forty 3-day-old piglets producted by pregnant sows in experimental groups and blank group were randomly selected and taken 4 mL 1×10^8.0TCID₅₀/mL F10 virus culture.The PEDV morbidity of piglets in blank group was 100% after injection and the antibodies were negative;10% piglets in blank group had mild diarrhea symptoms,the protection rate was up to 90%,antibody of passive immunity in piglets lasted for more than 35 days.Virus titer of mutant strain of PEDV-GF10 improved a lot by suspension cell culture,the PEDV-GF10 inactivated vaccine was safe,and could effectively prevent and control the variation strain of PEDV in China.     

Study on Synergistic Effect of VA5 Immunopotentiator on Pigeon NDV Inactivated Vaccine

This study was designed to evaluate the synergistic effect of VA5 immunopotentiator on pigeon ND4416 inactivated vaccine.160 healthy pigeons were randomly divided into four groups,including ND4416 strain inactivated vaccine group (NDV group),ND4416 strain inactivated vaccine and immunopotentiator (VA5) mixed group (NDV+VA5 group),La Sota inactivated vaccine group (La Sota group) and normal saline as the control group (C group),to assess their vaccine efficacy against virulent pigeon NDV by serological analysis and animal testing.Pigeons sera were collected at different time points after immunization and measured the HI antibody titer of each group.The results showed that VA5 immunopotentiator significantly improved the serum antibody level of pigeons immunized with pigeon Newcastle disease inactivated vaccine (P<0.05).In addition,comparative test of spleen lymphocyte transformation was conducted at various time points after immunization.The results indicated that VA5 effectively stimulated the lymphocyte transformation of immune pigeon.Pigeons in each groups were challenged with ND4416 strain at the 30th,90th and 180th d after immunization.The results presented that the NDV+VA5 group had 100% protection rate and higher than La Sota group.The duration of immunization test showed that the antibody titer of NDV+VA5 group reached peak 11.20log₂ at the 21st d,remained 7.50log₂ at 180th d,and the protection rate remained 100% at 180th d.It indicated that VA5 immunopotentiator sustained the immune duration of pigeon NDV vaccine up to 180 d.Moreover,the in vitro detoxification test results suggested that VA5 immunopotentiator reduced the in vitro detoxification cycle of pigeons after challenge.Overall,this study suggested VA5 immunopotentiator could significantly improve the immune efficacy of pigeon Newcastle disease inactivated vaccine,which provided a basis for further enhancing the efficacy of Newcastle disease vaccine,as well increased experimental data for the application of immunopotentiators.     

Evaluation of a Competitive Exclusion Culture and Megan Vac 1 on Salmonella Typhimurium Colonization in Neonatal Broiler Chickens

The present study was designed to evaluate the effect of individual or simultaneous application of 2 products, a competitive exclusion culture (CEC) or Megan Vac 1 (MV), for bioefficacy in reducing Salmonella Typhimurium (ST) cecal colonization in broiler chicks following experimental challenge. In experiment 1, CEC and MV were applied to day-of-hatch broiler chicks, and chicks were experimentally challenged with ST approximately 48 h later. In control chicks, ST was recovered at a level of 3.84 log₁₀ cfu/g following direct plating of cecal contents, and 12 of 19 (63.15%) cultured individual ceca were positive following selective enrichment. In chicks receiving CEC by spray application on day of hatch, a numerical reduction in ST recovered from cecal contents (2.63 log₁₀ cfu/g) and a significant reduction (P < 0.05) in recovery of ST from cultured ceca following selective enrichment (4 of 18, or 22.2%) was observed when compared with controls. Significant reductions in ST cecal colonization in chicks treated with MV alone were not observed in experiment 1. In experiment 2, chicks received day-of-hatch spray application of CEC alone, MV alone, or CEC and MV as a combined application immediately prior to or within 24 h of chick placement. When chicks were experimentally challenged with ST 48 h posthatch, significant reductions (P < 0.05) in cecal colonization by ST were observed with each experimental group when compared with nontreated controls. These data suggest that both commercially available products, alone or in combination, are efficacious in reducing cecal colonization in broiler chicks challenged with ST.     

Monitoring the Immune Status of Broilers Against Reoviruses Using Challenge and Serologic Data

Reoviruses are an important cause of suboptimum performance in commercial broilers worldwide. Integrators use the enzyme-linked immunosorbent assay against the S1133 antigen for monitoring serum of breeders for indicating pullet vaccine success. However, without correlating serology to reovirus challenge, it is difficult to determine whether titers reflect protective immunity. We developed a broiler challenge test against 2 common reovirus isolates (2408 and S1133) to evaluate the efficacy of reovirus pullet vaccine programs. Two reovirus serologic and challenge studies were undertaken using chicks from broiler integrators from the southeastern United States. Breeder flocks, from which the chicks were obtained, received at least 1 live and 2 inactivated reovirus vaccines during their pullet phase. One-day-old progeny were collected from 6 breeder flocks. At 1 d of age, 20 chicks from each broiler flock were bled, and serum was analyzed for antibodies. At 3 to 4 d of age, 20 progeny per flock were challenged with the 2408 reovirus by intratracheal route. At 10 to 14 d of age, another 20 birds per flock were challenged with the S1133 reovirus by footpad. Twenty birds per flock were used as nonchallenged controls. At 3 wk of age, all birds were killed and weighed. Percentage of protection was calculated for each flock based on the absence of gross lesions. Flocks with at least 50% protection were considered well protected. Most flocks were well protected against both viruses. The percentage of protection correlated with day-old enzyme-linked immunosorbent assay titers. Chicks from younger hens had higher titers and the best protection against challenge. Producers, whose hen flocks were monitored herein, were doing a good job of immunizing pullets against reovirus. They are now using reovirus progeny challenge studies along with breeder antibody titers to determine vaccination success of their pullets.     

猪瘟病毒及其致病机制研究进展

猪瘟（CSF）是猪的一种高度接触性传染病，该传染病可分为急性、亚急性、慢性、非典型性和不明显型。急性CSF由强毒株引发，一般导致高发病率和死亡率，而弱毒病毒感染则表现不明显。由于疫苗的广泛应用，有效地控制了猪瘟的大流行，减少了急性死亡。但从20世纪80年代以后，临床症状不典型且病程变长的非典型性猪瘟（或慢性猪瘟）成为该病的主要发生形式，持续感染普遍存在，疫苗的预防效果明显下降，使猪瘟防制遇到了新的困难。以目前人类对猪瘟的认识水平，尚难以从分子水平解释这一新变化的成因，这是因为对猪瘟病毒致病机理及其分子基础的认识深度不够。就此，文章综述了猪瘟及猪瘟病毒研究进展，主要涉及CSFV生物学特性、致病机制及其防控，希望能为猪瘟防控提供新的思路和对策。     

免疫佐剂研究进展

佐剂的主要作用是提高抗原（免疫原）的免疫原性和免疫反应的可持续性，它能引导机体的免疫系统对抗原产生体液免疫或细胞免疫反应。对佐剂的选择取决于免疫的目的，从用途上分，佐剂可分为试验用佐剂和疫苗用佐剂。前者主要用于特异性抗体的制备，而后者则作为疫苗的必要成分。文章主要介绍目前常用的几种佐剂包括铝盐佐剂、弗氏佐剂、免疫刺激复合物（ISCOM）、脂质体和CpG及其在科研和疫苗中的应用。     

抗原表位及其在血吸虫疫苗研究中的应用

血吸虫病是世界上危害最严重的寄生虫病之一，其疫苗的研究是世界血吸虫病防治的一项工作重点也是一大难题。抗原表位是疫苗设计和免疫识别的基础，本文对抗原表位在疫苗设计中的分子理论基础做了阐述．介绍了其在血吸虫疫苗设计中的应用，并提出了一些问题与展望。     

H5N2与H5N1禽流感油乳灭活疫苗免疫鹅群对H5N1流行株攻毒的保护效力及母源抗体对免疫效力的干扰

应用H5N2和H5N12种类型禽流感油乳灭活疫苗分别免疫鹅群,观察比较了二者对H5N1型高致病性禽流感病毒的攻毒保护效力。结果表明,在同等剂量免疫条件下,从发病率、死亡率和泄殖腔排毒规律3项指标综合评价来看,H5N1灭活苗水禽免疫组对高致病性禽流感H5N1流行株攻毒的保护效率较H5N2灭活苗理想,且水禽禽流感母源抗体对灭活苗免疫具有一定的干扰作用。     

马链球菌兽疫亚种类M蛋白亚单位疫苗小鼠免疫试验

为获得控制猪链球菌病安全高效的疫苗，本试验进行了马链球菌兽疫亚种类M蛋白亚单位疫苗的研制。应用热酸法提取马链球菌兽疫亚种ATCC35246株类M蛋白，并分别采用羟基磷灰石（HAT）层析和冷酒精沉淀法进行纯化，结果得到较纯的类M蛋白。用热酸提取的粗制类M蛋白、2种纯化的类M蛋白及全菌苗免疫小鼠，结果保护率分别为92％（11／12）、100％（12／12）、100％（12／12）和83％（10／12），表明类M蛋白亚单位疫苗有进一步开发的必要。