Studies on the mechanism of vaccinal immunity to Marek''s disease

Current knowledge of the nature of the antigens and of the host immune responses in vaccinal immunity to Marek's disease is reviewed. It is suggested that a two-step mechanism of resistance operates. The first step involves humoral and cell-mediated responses directed against viral antigens; the second step occurs after challenge with Marek's disease virus and consists of cellmediated responses directed against tumour cells.     

ND─EDS二联油乳剂灭活苗的研制

用鸡新城疫（ＮＤ）克隆３０毒株接种鸡胚，鸡产蛋下降综合症（ＥＤＳ）ＢＨ９１毒株接种鸭胚，分别收获ＮＤ鸡胚尿囊液毒和ＥＤＳ鸭胚尿囊液毒，用福尔马林灭活，二者混合后，加入１０号白油油相中，制成ＮＤ─ＥＤＳ二联油乳剂灭活苗。该苗接种在产前母鸡，可使接种鸡获得对ＮＤ和ＥＤＳ强毒攻击坚强的抵抗力。该苗安全、稳定，４℃保存期至少可达１２个月以上，适用于基层推广使用。     

Serotypes of Escherichia coli strains isolated from piglets with diarrhea in swine industrial farms

Serotypes of E. coli strains isolated from piglets, which died with symptoms of diarrhea in 9 swine industrial farms, were determined. Large numbers of serotypes (from 16 to 27) in individual farms were detected. The sets of serotypes from 9 investigated farms differed among each other significantly, depending on the farm and time of examination. It was found that more than one serotype of E. coli may exist in the pig body and contribute to the development of disease. The predominant serotypes, i.e. those comprising more than 10% of serologically determined strains, were found to exist in 6 of the investigated farms and not in the remaining ones. Among the predominant serotypes, particularly important seem to be strains with K88 antigen. For prophylaxis of piglet colibacteriosis in industrial farms in Poland two vaccines for sows are recommended: one containing the K88 antigen only and the other the following serotypes: 0149:K91,K88; 020:K57; 020:K83; 0157:K88; 01:K1; 0136:K78; 024:K?; 078:K80 and 0118:K? Strains belonging to these serotypes were the most prevalent in our strain collection.     

Les vaccins dans la prevention de la rhinotracheite infectieuse du chat adjuvant BCG gel d''alumine (preparation, controle, immunite)

Immunogenicity of different vaccines against the main viral diseases was compared: feline infectious rhinotracheitis, feline panleucopenia virus and calicivirus. These inactivated vaccines developed higher protective activity when adjuvants such as BCG or aluminium hydroxide were used. Animals vaccinated and boostered with an identical dose of these vaccines resisted the viral challenges. Neutralizing antibodies titers obtained with BCG adjuvated vaccines were twofold higher than those containing aluminium hydroxide.     

Combined vaccination of cats against panleucopenia and rabies

In a previous paper [3], we demonstrated that it was possible to vaccinate cats with a combined vaccine against Panleucopenia and Rabies.The purpose of this paper is to sum up the tests for safety and potency, carried out in cats vaccinated with a new combined vaccine against Panleucopenia and Rabies. This vaccine is different from that mentioned in the previous paper. The new Rabies vaccine is a vaccine adjuvanted by aluminium hydroxide.First of all, we shall examine the means and methods implemented and then, present the comparative results obtained with the two types of Rabies vaccine (whether adjuvanted or not) combined with the Panleucopenia live vaccine.     

A new freeze-dried living virus vaccine against sheep-pox

A sheep-pox virus strain has been adapted and multiplied in primary lamb kidney cell cultures. The main characteristics of the strain have been verified in vitro after clones were isolated, and the results confirmed its identity. The safety and the potency of the strain have been investigated in sheep.

The inoculation of the strain to sheep was followed by a post-vaccinal reaction materialised by a nodule at the site of inoculation and an increase of temperature by about 1°C. No reactions adversely affecting pregnancy have been noted. Immunisation was demonstrated by an increase in the level of neutralising serous antibodies and protection against the pathogenic virus. The immunity tended to decrease during the second year after primovaccination and a yearly booster vaccination appeared to be necessary. Primovaccination of lambs over 2 months of age produced a better immunity, especially when the lambs were born from vaccinated ewes.

This strain forms the active principle of a freeze-dried vaccine containing no adjuvant of the immunity.     

鸡新城疫——减蛋综合征二联油佐剂疫苗的研制

应用鸡新城疫（ＮＤ）ＬａＳｏｔａ株和减蛋综合征（ＥＤＳ－７６）ＬＡ３株,分别接种鸡胚和鸭胚增殖病毒,血凝价分别达≥１：１２８０和≥１：１００００时,收取病毒,经福尔马林灭活,按一定比例加入吐温－８０、油佐剂制成ＮＤ－ＥＤＳ－７６二联疫苗,经无菌检验、安全性试验、剂量选择、保护性试验、免疫效果和免疫期测定及保存期观察,结果表明：该二联苗安全性好,于蛋鸡开产前１月皮下注射１ｍＬ／只,２５ｄ后ＮＤ和ＥＤＳ－７６抗体可先后达到高峰,免疫期１年。保存期４℃为１年,２０℃为３个月。     

检测EDS76病毒抗体Dot—ELISA方法建立的及应用

建立了检测ＥＤＳ７６病毒抗体Ｄｏｔ－ＥＬＩＳＡ方法。待检血清最适稀释度为１∶１０,ＥＤＳ７６病毒ＤＥＦ细胞培养物最佳工作浓度为１∶５,ＨＲＰ－ＭｃＡｂ工作浓度为１∶４００。所建方法与常见几种鸡的传染病血清无交叉反应,１２０份临床样本中检出６６份阳性。     

鸡产蛋下降综合症(EDS—76)灭活油乳剂苗的研究 Ⅰ.灭活油乳剂苗的制备

在本试验中,司本-80和硬脂酸铝加入油相,吐温-80加入灭活的EDS-76尿囊毒为水相制备成油乳剂苗。福尔马林灭活病毒制备的疫苗其免疫效果高于热灭活病毒制备的疫苗,免疫后三周,前者的HI抗体水平达9.5log_2,而后者仅为4.0log_2.福尔马林灭活病毒制备的疫苗于腹腔、皮下注射小白鼠、豚鼠、兔子和10倍剂量接种产蛋鸡,结果均无不良反应;该疫苗为完全油包水剂型、不导电,滴于冷水表面不扩散,亲水亲油平衡值(HLB)为6.67;镜下所见疫苗颗粒为0.5μ直径大小。4℃存放6个月稳定,有效期至少6个月。     

不同条件对ND、EDS—76病毒血凝性影响的观察

分别观察了不同稀释液、不同感作温度、不同红细胞浓度及不同感作时间对ND、EDS－76病毒HA效价、血凝特性及血凝解脱现象的影响。结果表明，在进行HA试验时，以PH7．2的PBS液为稀释液、0．5％鸡红细胞为指示系统、在37℃下感作20min或室温下感作30min为最适试验条件。各样品在0．5％红细胞下测得的HA效价比0．8％红细胞时平均高0．25－0．5个滴度，其它情况下测得的HA效价基本相同，但红细胞的凝集状态及观察结果的时间有所不同。其中，感作温度越高（37℃），出现结果越早，且凝集现象越明显，但解脱作用发生得也越快。ND病毒所引起的血凝现象仅可持续2h左右，而EDS－76病毒引起的血凝现象可持续至24h不发生解脱，这一特性可作为鉴别2种病毒的1个指标。