大肠杆菌油佐剂灭活苗免疫雏鸡抗体消长规律的研究

用鸡源致病性大肠埃希氏菌Ｏ２血甭型制成的油佐剂灭活苗对１５日龄雏鸡进行免疫接种，以测定其抗体消长规律；对免疫后不同抗体滴度的雏鸡进行了攻毒试验。结果表明，免疫１周后可监出抗体，２－３周抗体达到高峰，抗体可持续１０周左右，抵抗同型大肠杆菌攻毒的最低抗体滴度为１：１６－１：３２，免疫保护期可达２个月以上。     

安宁河流域鸭瘟、鸭霍乱综合防制研究──免疫鸭体内巴氏杆菌抗体消长规律

以巴氏杆菌Ａ群菌苗免疫建昌鸭后,测定其抗体消长规律,对攻毒前后抗体进行比较,并用血凝抑制试验鉴别其抗体类型。结果表明：（１）注苗后５～６ｄ抗体就可达４个ｌｏｇ２及其以上,２９日龄鸭免疫后４０ｄ内,抗体在４个ｌｏｇ２及其以上,５０ｄ时不足４个ｌｏｇ２;３月龄鸭免疫后１１３ｄ内,抗体在４个ｌｏｇ２及其以上,１４６ｄ时为３．８１个ｌｏｇ２,１６５ｄ为２．４１个ｌｏｇ２;（２）攻毒后１５ｄ,抗体普遍比攻毒前下降约１个滴度,但攻毒后３０ｄ抗体比攻毒前高１～２个滴度。当抗体达４个ｌｏｇ２时,具有完全保护性,能抵抗人工感染和自然感染;（３）巴氏杆菌抗体以ＩｇＭ为主（ＩｇＧ甚微）,注苗后的回忆反应很不明显,这可能是巴氏杆菌苗免疫期较短的重要原因。     

鸡大肠杆菌自家苗血清抗体的消长规律研究

本试验用某鸡场分离的大肠杆菌制成铝胶佐剂灭活苗,免疫接种15日龄雏鸡,对免疫后其抗体消长规律进行测定,并对不同抗体滴度的雏鸡进行攻毒试验。结果表明,一免后1周可产生抗体,3周抗体达到高峰,抗体可持续10周左右。二次免疫后抗体水平显著高于一次免疫,且抗体高峰持续时间更长,抵抗同型大肠杆菌攻毒的最低抗体滴度为1:16～1:32,免疫保护期可达4个月左右。     

禽流感灭活疫苗的研制与疫苗免疫试验

将分离到的３个不同毒株禽流感病毒分别接种９～１０日龄鸡胚,收获尿囊液,经甲醛灭活,配以油佐剂制成油乳剂灭活疫苗,接种５周龄的非禽流感疫苗免疫鸡,注苗后无不良反应。免疫后每周采血一次,测ＨＩ抗体,结果表明免疫后７天抗体普遍上升１～２个滴度,１４天平均抗体水平在７．５ｌｏｇ２以上,２１天抗体水平在８～９ｌｏｇ２以上,免疫后２１天攻毒,免疫组鸡无临床症床和死亡,对照组出现临床症状,但未死亡,攻毒一周后,     

安宁河流域鸭瘟,鸭霍乱综合防制研究

以巴氏杆菌Ａ群菌苗免疫建昌鸭后，测定其抗体消长规律，对攻毒前后抗体进行比较，并用血凝抑制试验临别其抗体类型。结果表明：（１）注苗后５－６ｄ抗体就可达４个ｌｏｇ２及其以上，２９日龄鸭免疫后４０ｄ内，抗体在４个ｌｏｇ２及其以上，５０ｄ时不足４个ｌｏｇ２；３月龄鸭免疫后１１３ｄ内，抗体在４个ｌｏｇ２及其以上，１４６ｄ时为３．８１个ｌｏｇ２，１６５ｄ为２．４１个ｌｏｇ２；（２）攻毒后１５ｄ，抗体普遍比攻主     

鸡传染法氏囊病中和抗体动态水平监测及其应用的研究

用鸡胚成纤维细胞的微量血清中的（ＳＮ）试验跟踪抽检出了同群两种不同免疫程序的１２组次共１４２只鸡的传染性囊病（ＩＢＤ）中和抗体滴度。结果表明，该群日龄雏鸡的母源抗体水平高达８．３ｌｏｇ２并且较整齐，雏鸡母源体半衰期约为４．３－５．０天；用ＳＮ免疫监测不同的等距离及其实际效果，说明在中和抗体滴度降至６．０－６．５ｌｏｇ２（１５－１８日龄）时首免效果最好。该方法准确且繁感性高，可用于鸡群免疫监测，指导     

Ⅱ型猪链球菌S2株在兔中免疫原性的研究

本文对Ⅱ型猪链球菌Ｓ２株进行了研究。作者用Ｓ２制备了３种不同抗原：荚膜多糖,多糖蛋白复合物,灭活菌苗。通过血清学方法证明荚膜多糖（ＣＰＳ）,多糖蛋白复合物与Ｓ２株有共同的抗原,免疫兔后,保护指数在１／２至２／２之间。本试验用ＥＬＩＳＡ法检测了３种抗原的免疫反应。免疫荚膜多糖组在第２周就能检测到抗体,并持续到第４周,免疫多糖蛋白复合物组在第４周才有抗体出现,免疫灭活苗组第２周出现较低滴度的抗体,第４周就降到零。从抗体滴度看,ＣＰＳ反应快,多糖蛋白复合物产生抗体迟,灭活苗产生抗体滴度低。本文还比较了３种不同佐剂（铝胶,蜂胶,ＥＭＵＬＳＩＧＥＮＲ）对３种抗原的佐剂活性作用。铝胶能促使兔体对荚膜多糖产生抗体,蜂胶次之,ＥＭＵＬＳＩＧＥＮＲ最差。     

传染性法氏囊病免疫程序研究

本试验选用１日龄ＩＢＤ母源抗体参差不齐的伊莎褐壳蛋雏鸡和ＩＢＤ母源抗体水平基本一致的迪卡蛋雏鸡，用ＩＢＤＶ标准Ｉ型弱毒疫苗Ｄ－７８和油乳剂灭活苗进行免疫程序筛选试验。结果表明：１．雏鸡母源抗体参差不齐情况下，３日龄用ＩＢＤ弱毒苗首免，１７日龄用油乳剂灭活苗二免为优良免疫程序。２．雏鸡母源抗体水平基本一致情况下，１４日龄用ＩＢＤ弱毒首免，２４日龄用油乳剂苗二免为优良免疫程序。     

鸡传染性法氏囊病Vero细胞弱毒疫苗免疫效果的研究

鸡传染性法氏囊病（ＩＢＤ）Ｖｅｒｏ细胞弱毒疫苗（ＶＣＶ９０１）病毒滴度为１０￣（７．３）～１０￣（８．３）ＴＣＩＤ＿（５０）／０．０５ｍｌ．疫苗经皮下、肌内、点眼－滴鼻和口服途径免疫接种雏鸡，均表现出良好的免疫原性。皮下接种１４日龄雏鸡，免疫后８、１４和２１天攻毒，保护数分别为２／６、６／６５／６，如在３５日龄再加强免疫一次，于二免后７０天和１１５天攻毒．其保护数分别为６／６和５／６．疫苗的最小免疫剂量为１０￣５ＴＣＩＤ＿（５０）／只，用１０、５０和１００培免疫剂量免疫雏鸡，临床表现均安全，不影响雏鸡增重．经易感雏鸡连传５代，疫苗毒力不返强．温苗在－２０℃～－２５℃至少保存一年，在０℃可保存一周，疫苗对鸡无致瘤性．     

鸡传染性法氏囊病Vero细胞弱毒疫苗免疫效果的研究

鸡传染性法氏囊病Ｖｅｒｏ细胞弱毒疫苗病毒滴度为１０＾７．３－１０＾８．３ＴＣＩＤ５０／０．０５ｍｌ。疫苗经皮下，肌肉，点眼－滴鼻和口服途径免疫接种雏鸡，均表现出良好的免疫原性。皮下接种１４日龄雏鸡，免疫后８，１４和２１天攻毒，保护数分别为２／６，６／６和５／６，如在３５日龄再加强免疫一次，于二免后７０天和１１５天攻毒，其保护数分别为６／６和５／６。疫苗的最小免疫剂量为１０＾５ＴＣＩＤ５０／只，用１     

鸡新城疫、传染性支气管炎、减蛋综合征、传染性脑脊髓炎四联灭活疫苗IB部分效力试验研究

采用《进口兽药质量标准》中传染性支气管炎灭活疫苗效力检验方法,对ND-IB-EDS76-AE四联灭活疫苗IB部分进行了效力检验。先用IBH120活疫苗作基础免疫,免疫后3～4周采血,然后用四联苗加强免疫,四联苗免疫后3～4周采血,将二次血清分别作IBHI试验。结果显示,IBH120活疫苗免后3～4周,其IBHI效价为3．6～4．610g2（1：12—1：24）,用四联苗加强免疫3～4周后,IBHI达6．2—8．610g2（1：74～1：388）,四联苗免后的IBm抗体滴度比免前提高了4．9～26倍,均大于3倍的标准。试验证明,该方法用于四联苗内IB部分效力检验是可行的。     

H7亚型禽流感病毒灭活疫苗的研制及其免疫效果研究

以H7N3亚型禽流感病毒接种鸡胚,收取鸡胚液为抗原研制禽流感病毒灭活疫苗,并对制苗抗原以及疫苗的物理性状、安全性、免疫效力、免疫剂量和保护期等进行了试验,结果表明,该灭活疫苗安全性好,对28日龄鸡的最佳免疫剂量为0.5 mL/只,抗体临界保护值为5log2,免疫后6周HI效价达到高峰值9.4log2,以后逐渐下降,第20周抗体仍能维持较高水平。此外,交叉免疫保护试验表明,同一亚型之间具有良好的免疫保护作用,而亚型间缺乏坚强的交叉保护作用。     

Is there a benefit from an early booster vaccination in the control of equine influenza?

Conventional equine influenza vaccination schedules consist of a primary course of two vaccinations given 4-6 weeks apart followed by a third vaccination (booster) given approximately 5 months later. In between the primary course and the third vaccination, horses are generally considered not to be adequately protected against influenza. This study aimed to investigate whether Thoroughbred foals would benefit from a vaccination schedule in which the third vaccination was given earlier than in conventional vaccination schedules. The vaccines used were an inactivated whole virus equine influenza vaccine and an inactivated whole virus combination vaccine containing equine influenza and equine herpesvirus antigens. Four groups of foals were vaccinated with the two vaccines according to a conventional and an accelerated vaccination schedule in which the third vaccination was given 14 weeks after the first administration. In both groups, the fourth vaccination was given at the normally recommended interval of 26 weeks after the third vaccination for the combination vaccine and 52 weeks after the third vaccination with the influenza only vaccine. The horses were 4-11 months of age and seronegative for influenza. Immunological responses after vaccination were monitored for several months using the single radial haemolysis test. The results indicated that 28 weeks after the first vaccination, antibody levels in horses vaccinated according to the accelerated schedule were not significantly higher than in horses vaccinated according to the conventional schedule. In addition, the total level of antibody production (area under the curve) was not significantly different at that point although antibody titres were slightly higher (but not significantly so) between 16-30 weeks in the accelerated schedule. Between the third and fourth doses, horses vaccinated according to the accelerated schedule had antibodies against influenza below the level required for clinical protection for 39 and 18 weeks for the influenza only and the combination vaccine, respectively, whereas those vaccinated according to the conventional schedule had antibody titres below the level for clinical protection for 9-15 weeks in the corresponding period for both vaccines. Horses vaccinated according to the accelerated schedule with the combination vaccine had lower antibody titres after the fourth vaccination than those vaccinated according to the conventional schedule after the third vaccination, although antibody titres prior to vaccination were similar. For the influenza only vaccine, titres after the accelerated fourth administration were not different to those after the conventional third vaccination. There was no benefit from early booster vaccinations with the vaccines used in this study, so for these vaccines the conventional schedule provided better protection than the selected accelerated alternative. This may contrast with some other vaccine formulations, although a direct comparison using similar protocols has not been made.     

Cell mediated and humoral immune response of chickens to inactivated oil-emulsion infectious bronchitis vaccine

A lymphocyte transformation microassay was used to study cell mediated immunity (CMI) in chickens following primary and secondary vaccination with inactivated oil emulsion infectious bronchitis (IB) vaccine and subsequent challenge with Massachusetts-41 (M-41). Humoral immunity was monitored for comparison, using the haemagglutination inhibition (HI) microassay. Positive stimulation indices (2 to 2.7 after primary and 2 to 4.8 after secondary vaccination) were lower and HI titres were higher than those previously reported following primary and secondary vaccination with live IB vaccines. The highest HI titres appeared in birds which had received the inactivated vaccine as a secondary vaccination. Challenge of vaccinated and revaccinated birds resulted in strong HI and weak CMI secondary responses. There was no correlation between CMI and HI antibody production. Monitoring egg production and clinical signs showed that a high level of protection against challenge resulted from revaccination with an inactivated oil adjuvant vaccine.     

Immunization of cattle against Aujeszky's disease with inactivated adjuvant vaccine

The experiments with sheep and young cattle were carried out to test the immunizing efficacy of inactivated adjuvant vaccine against Aujeszky's disease. The vaccine application at doses of 1 ml and 2 ml to lambs at the age of eight to ten months caused the neutralizing antibody production with a significant rise of titres after revaccination. A survival of infection induced with a dose of 10(5.5) TKID50 of virulent virus was recorded in 62.5% of once vaccinated animals and in 87.5% of twice vaccinated animals. When applying different doses of vaccines (from 1 to 10 ml) to young cattle, the antibody reaction level was directly dependent on the inoculum quantity. The double inoculation of animals with vaccines of 2 ml and 5 ml caused the neutralizing antibody production at titres of 1:35, or 1:46. The animals, immunized with the live or inactivated IBR-vaccine possessing high antibody titres against IBR-virus, reacted upon the vaccination with inactivated Aujeszky's vaccine anamnestically, by early production of antibodies in high titres. Metaphylactic vaccination (2 ml of vaccine) of cattle in herds with an acute course days, however earlier during five days from the revaccination when it was carried out in seven days following the first vaccination.     

Local immunity in the respiratory tract of the chicken. II. The secretory immune response to newcastle disease virus and the role of IgA

The nature, specificity and characteristics of the secretory immune response in the respiratory tract of the chicken were investigated in young specific-pathogen-free chickens after vaccination with live lentogenic and inactivated Newcastle disease virus (NDV). Virus-neutralizing (VN) activity considerably exceeding transudation levels from serum were detected in lachrymal fluid, saliva and tracheal washes following infection by both ocular and oral routes. Heat inactivated virus inoculated into the trachea evoked neither serum nor secretory VN activity, whereas a commercial inactivated virus vaccine in mineral oil adjuvant stimulated high titres of serum antibody and some VN activity in tracheal fluids.Antibody in secretions limited, but did not prevent, reinfection of the trachea when birds were challenged 2 weeks later. In contrast to an elevation of circulating antibody titre, challenge induced only a repeated primary response of secreted antibody.All secretions contained IgA which, at least in saliva, accounted for 85% of its activity, the remainder being due to IgG. Fluorescent localization of immunoglobulin producing cells (IPC) demonstrated large numbers containing IgA in association with the upper respiratory tract, particularly in the Harderian gland which contained dense aggregations of plasma cells, many of which were producing IgA.It is concluded that the respiratory tract of the chicken possesses an antibody mediated secretory immune system analogous to that of mammalian species.     

Efficacy and duration of immunity of a combined equine influenza and equine herpesvirus vaccine against challenge with an American-like equine influenza virus (A/equi-2/Kentucky/95)

It has been recommended that modern equine influenza vaccines should contain an A/equi-1 strain and A/equi-2 strains of the American and European-like subtype. We describe here the efficacy of a modern updated inactivated equine influenza-herpesvirus combination vaccine against challenge with a recent American-like isolate of equine influenza (A/equine-2/Kentucky/95 (H3N8). The vaccine contains inactivated Influenza strains A-equine-1/Prague'56, A-equine-2/Newmarket-1/'93 (American lineage) and A-equine-2/ Newmarket-2/93 (Eurasian lineage) and inactivated EHV-1 strain RacH and EHV-4 strain V2252. It is adjuvanted with alhydrogel and an immunostim. Horses were vaccinated at the start of the study and 4 weeks later. Four, six and eight weeks after the first vaccination high anti-influenza antibody titres were found in vaccinated horses, whereas at the start of the study all horses were seronegative. After the challenge, carried out at 8 weeks after the first vaccination, nasal swabs were taken, rectal temperatures were measured and clinical signs were monitored for 14 days. In contrast to unvaccinated control horses, vaccinated animals shed hardly any virus after challenge, and the appearance of clinical signs of influenza such as nasal discharge, coughing and fever were reduced in the vaccinated animals. Based on these observations, it was concluded that the vaccine protected against clinical signs of influenza and, more importantly, against virus excretion induced by an American-like challenge virus strain. In a second experiment the duration of the immunity induced by this vaccine was assessed serologically. Horses were vaccinated at the start of the study and 6 and 32 weeks later. Anti-influenza antibody titres were determined in bloodsamples taken at the first vaccination, and 2, 6, 8, 14, 19, 28, 32, 37, 41, 45 and 58 weeks after the first vaccination. Vaccinated horses had high anti-influenza antibody titres, above the level for clinical protection against influenza, against all strains present in the vaccine until 26 weeks after the third vaccination.     

THE SEROLOGICAL RESPONSE OF CHICKENS TO AUSTRALIAN LENTOGENIC STRAINS OF NEWCASTLE DISEASE VIRUS

SUMMARY: Australian lentogenic Newcastle disease viruses were evaluated as uninactivated vaccines in Australian chickens, the response being evaluated by the production of haemagglutination-inhibition (HI) antibodies. Two viruses, V4 and PM9, induced high levels of antibody and were readily transmissible between chickens by contact exposure. Three other viruses were poorly immunogenic and poorly transmissible. Chickens vaccinated intramuscularly with the V4 strain produced higher HI antibody titres than chickens vaccinated by the orotracheal, intranasal and intraocular routes. HI antibody titres in chickens vaccinated with the V4 strain reached peak levels 3 to 5 weeks after vaccination and waned considerably during the next 2 to 4 weeks. However, low levels of HI antibody persisted for at least 36 weeks after vaccination. Intramuscular vaccination with the V4 strain of one-day-old chicks lacking maternal antibody to Newcastle disease virus resulted in 42–70% mortality and the survivors developed very high titres of HI antibody. Similar chickens inoculated orotracheally showed signs of depression and developed high titres of HI antibody, but there were no mortalities. Chickens 1-, 2-, 3- and 4-weeks-old and lacking maternally derived HI antibody to Newcastle disease virus suffered no adverse reaction to intramuscular or orotracheal vaccination. The antibody response of the 1-week-old chickens was considerably poorer than that of the older chickens. Following orotracheal vaccination with the V4 strain, chickens with low levels of maternally derived antibody responded with low levels of HI antibody. On the other hand, in the progeny of hens hyperimmunised with the V4 strain the production of active antibody following orotracheal vaccination was delayed until the level of passive antibody had declined considerably. There was no response to intramuscular vaccination in congenitally hyperimmune chickens. The minimum HI antibody inducing dose of V4 vaccine, when measured 3 weeks after vaccination of 6-weeks-old chickens, was 10^5.6 50% egg infectious doses.     

Intranasal vaccination of pigs against Aujeszky's disease. 4. Comparison with one or two doses of an inactivated vaccine in pigs with moderate maternal antibody titres

Intranasal (IN) vaccination of pigs with low levels of maternally-derived antibody (MDA) has previously been shown to confer good protection against challenge with virulent Aujeszky's disease virus (ADV). The objective of the present study was to determine the efficacy of IN vaccination with an attenuated ADV, in comparison with that of an inactivated vaccine given parenterally, in pigs with higher MDA titres at the time of vaccination. In one experiment, vaccinations were done at 6 weeks of age, and in another experiment pigs were vaccinated at 4 and/or 9 weeks of age. Two months after (the last) vaccination pigs were challenged intranasally with a virulent ADV. Protection was evaluated on the basis of mortality, periods of growth arrest, fever and virus shedding after challenge. The presence of MDA markedly depressed the serum-neutralizing antibody response after vaccination. Sensitisation occurred after parenteral vaccination with an inactivated vaccine despite high MDA levels. Although the intranasally-vaccinated pigs had lower levels of neutralizing antibody at the time of challenge, they were significantly better protected than pigs given 1 or 2 doses of the inactivated vaccine. Comparing the present results with those of a previous study, it appears that the efficacy of parenteral as well as intranasal ADV vaccination decreases with increasing levels of MDA at the time of vaccination.     

Duration of immunity induced by an adjuvanted and inactivated equine influenza, tetanus and equine herpesvirus 1 and 4 combination vaccine

An adjuvanted vaccine containing inactivated equine influenza, herpesvirus antigens, and tetanus toxoid was administered to young seronegative foals of 8 months of age by deep intramuscular injection in the neck (Group A). The first two vaccinations were given 4 weeks apart. The third was administered 6 months later. Another group of foals (Group B) was vaccinated according to the same scheme at the same time with monovalent equine herpes virus (EHV) vaccine (EHV1.4) vaccine. Antibody responses to the equine influenza (single radial haemolysis; SRH) and tetanus (ToBi ELISA) components of the vaccines were examined from first vaccination until 1 year after the third vaccination. The influenza components of the combination vaccine induced high antibody titres at two weeks after the second vaccination whereafter titres declined until the time of the third vaccination. After the third vaccination, the titres rose rapidly again to remain high for at least 1 year. Antibody titres against tetanus peaked only after the third vaccination but remained high enough to offer protective immunity for at least 1 year. Foals vaccinated with monovalent EHV1.4 remained seronegative for influenza and tetanus throughout the study. Four and a half months after the third vaccination of groups A and B, a third group of animals was vaccinated twice with monovalent EHV1.4 vaccine 4 weeks apart (Group C). Two weeks after the administration of the second dose in the later group, all groups (A, B, C and an unvaccinated control group D) were challenged with EHV-4. Vaccinated foals (Group A, B, C) showed a clear reduction of clinical symptoms and virus excretion after EHV-4 challenge compared with the unvaccinated control foals. No difference could be demonstrated among the vaccinated groups, suggesting that the combination vaccine protects as well as the monovalent vaccine. In EHV1.4-vaccinated foals both antigenic fractions induced clear protection up to 6 months after vaccination (9). It can therefore be anticipated that the efficacy of the combination vaccine against EHV-1 challenge is similar to the efficacy against EHV-1 induced by EHV1.4 vaccination.