Vaccines and principles of immunization

This article discusses the production of the various classes of vaccines and compares the advantages and disadvantages of each. Adjuvants, combination vaccines, heterologous viral vaccines, and vaccination failure are discussed briefly. Reported adverse reactions to vaccination are described at length. Essential vaccination for several exotic species is given.     

如何科学合理地进行免疫

一、免疫的目的和种类 通常我们所说的免疫接种是将疫苗或菌苗经过一定途径接种于动物体，使动物在不发病的情况下产生免疫应答，在一定时间内对某种传染病具有抵抗力。免疫力可以分为先天性免疫和获得性免疫两种。     

Intraperitoneal immunization against necrobacillosis in experimental animals.

Experiments employing recently developed mouse models indicated that intraperitoneal immunization with the cytoplasm (intracellular fraction) of Fusobacterium necrophorum protected the animals from a lethal challenge of the pathogen. The critical immunization schedule needed to achieve complete protection involved six weekly intraperitoneal doses of the intracellular antigen. Livers of immunized mice were cleared of infecting fusobacterial within 24 hours whereas those of nonimmunized mice harboured increasing numbers of hte bacteria. Sera from both groups did not protect recipient mice form developing liver abscesses after challenge. Sheep immunized intraperitoneally with 20 mg of cytoplasmic protein given in three doseases were protected against the development of abscesses induced by F. necrophorum.     

Parenteral immunization of pigs against infection with Treponema hyodysenteriae.

Six intravenous injections of formalin-inactivated Treponema hyodysenteriae were given to 8 specific-pathogen-free pigs at 6-day intervals. The 8 vaccinated and 8 control pigs were challenged intragastrically with pure cultures of T hyodysenteriae 7 and 8 days after the last intravenous injection. Clinical signs of swine dysentery were observed in all 8 control pigs, but was observed in only 1 of the immunized pigs. Three control pigs died. These findings suggest that parenteral immunization with T hyodysenteriae provided a marked degree of protection against subsequent intragastric challenge exposure with the homologous isolate of T hyodysenteriae.     

Prevention of edema disease in pigs by passive immunization.

The effect of treatment with verotoxin 2e (VT2e) specific antiserum was evaluated in 3 Danish pig herds with edema disease (ED). The antiserum was prepared by immunizing horses with a VT2e toxoid. The study was performed as a randomized blind field trial with parallel treatment and control groups. There were approximately 50 piglets in each group in each of the 3 herds and 741 piglets were included in the study (244 from herd A, 249 from herd B, and 247 from herd C). Treatment groups received 2, 4, or 6 mL anti-VT2e serum intramuscularly the day before weaning. Control groups were treated with 6 mL normal horse serum or 6 mL RPMI 1640 medium as placebo. All pigs that died in the trial period (1 d before weaning to 44 d after weaning) were examined pathologically and microbiologically. Mortality due to ED, mortality due to other causes, and adverse effects due to treatment were recorded. As there was no mortality due to ED, herd B was excluded from statistical calculations on mortality. The content of horse antibodies specific to VT2e in serum from pigs was analyzed in an indirect ELISA. A higher dose of anti-VT2e serum was reflected in higher optical density values in the indirect ELISA. Transient adverse reactions, seen as vomiting, ataxia, and cyanosis, occurred shortly after the injection of horse serum in 1.5% of the pigs, and one pig died. There were no statistically significant differences in mortality due to other causes among the 3 treatment groups in herds A and C. Only pigs from which F18+, VT2e+, ST-, LT- hemolytic E. coli (0139 or O-rough) was isolated were diagnosed as dead due to ED. Deaths due to ED in the control groups were 8.1% and 12.0% in herds A and C, respectively, compared with 0% and 0.7% in the corresponding serum groups. The difference between treatment and control groups was statistically significant (P<0.0001). It was not possible to establish an effect of dose (2, 4, or 6 mL) of anti-VT2e serum, because only one pig died of ED in the treatment groups. It was concluded that passive immunization by intramuscular injection of a VT2e-specific antiserum can be used for protecting piglets against ED.     

Coarse-spray immunization of one-day-old broilers against enteric reovirus infections.

Coarse-spray (CS) administration of a commercial S1133 reovirus vaccine was evaluated in 1-day-old specific-pathogen-free broilers for prevention of clinical infection induced by intratracheal challenge with two enteric reovirus isolates. In Expt. 1, chickens were challenged at 4 days of age with either the 2408 or CO8 isolate. In Expt. 2, chickens were challenged at 7 days of age with either isolate. In Expt. 3, chickens were challenged at 3, 5, or 7 days of age with the 2408 isolate. In Expt. 1, vaccinated birds showed significant protection against challenge with either isolate at 4 days of age as measured by morbidity, mortality, gross lesions, and body weight. In Expt. 2, vaccinated birds showed greater protection against challenge at 7 days of age. In Expt. 3, resistance in vaccinated birds increased with time between vaccination and challenge. Vaccinated birds challenged at 3 days of age showed no significant protection, whereas vaccinated birds challenged at 5 or 7 days of age had increased resistance. This vaccine did not induce a drop in weight gain, morbidity, mortality, or microscopic lesions in the tendons.     

Prenatal immunization against experimental enteric colibacillosis in piglets.

To establish a model for the study of prenatal immunization against enteric colibacillosis a proportion of the litters of seven sows were immunized in utero 18 to 22 days before term by intra-amniotic and intramuscular injection of Escherichia coli antigen and the litters challenged at birth with either homologous or heterologous strains. Protection against homologous challenge was demonstrated in some but not all vaccinated piglets. The study was severely compromised by the occurrence of intrauterine death in a significant proportion of vaccinated piglets.     

提高鸡免疫力的基本条件

优化鸡的免疫力就是给鸡提供优良的管理措施、充足的营养水平、良好的卫生和环境条件,只有认清这些影响免疫状态的因素,才可能获得最佳的经济效益。     

Paramyxovirus disease in racing pigeons. Clinical aspects and immunization. A report from the Netherlands

Since 1981 a highly contagious viral disease causing high morbidity and low mortality in racing pigeons has spread over Europe. The virus belongs to the avian paramyxovirus sero group I. Clinical signs include watery droppings, polydypsia and neurologic signs in a high proportion of infected animals. Definitive diagnosis can be made by virus isolation in cell cultures or chicken embryos, and virus identification by haemagglutination and haemagglutination inhibition (HI) tests. The HI test, using sera from suspected animals, is a useful clinical tool to confirm the diagnosis. The most important differential diagnosis is salmonellosis. Good immunity against this disease can be acquired by subcutaneous vaccination with an inactivated oil adjuvant poultry NDV-vaccine. For the benefit of pigeon racing a plea is made for compulsory vaccination in countries in which the disease is endemic.     

Preparation of B lymphocyte-specific alloantisera by skin implant immunization of cattle.

B lymphocyte-specific antisera were prepared by immunizing cattle on either one or two occasions with a subcutaneous implant of allogeneic skin and subsequently absorbing the antisera with platelets. After absorption 15/26 antisera displayed B lymphocyte-specific activity. Titres against B-enriched cells were 8-64 while residual titres against B-depleted cells were 1-8. In comparison, 3-6 immunizations with allogeneic leucocytes produced antisera of similar peak cytotoxic titres against donor PBL, and after platelet absorption 8/15 antisera displayed B lymphocyte-specific activity. Titres against B-enriched cells were 8-64 while residual titres against B-depleted cells were 2-8. The skin implant method was less time-consuming than the leucocyte immunization method.     

Protection of foals against experimental Rhodococcus equi pneumonia by oral immunization.

Two groups of three one to three week old foals were immunized orally on four occasions over five weeks with two strains of Rhodococcus equi, a clinical isolate from a pneumonic foal and a laboratory passaged Congo red negative variant of this strain. Three nonimmunized foals of similar age acted as controls. Three weeks after the last immunization, all foals were challenged on five occasions over seven days by aerosol infection with about 10(10) of the pneumonic foal isolate on each occasion. Control foals became seriously ill and were euthanized. Immunization with either strain protected foals equally against the challenge, and resulted in rapid lung clearance. Oral immunization can thus protect foals against severe challenge with R. equi. The proteins associated with Congo red colony staining appear not to be involved in protective immunity.     

狂犬病的免疫预防方法

在进行狂犬病免疫预防时必须特别注意的是所使用的狂犬病疫苗、抗狂犬病血清和人源狂犬病免疫球蛋白的制品质量一定要符合国家标准要求,只有这样才能达到免疫预防的预期效果。一旦被带毒动物致伤感染,病毒便开始在伤口局部复制繁殖;病毒与外周神经结合,便开始向中枢神经系统移动;出现症状,死亡几乎不可避免。没有被动物咬伤前进行的免疫称为暴露前免疫,被动物咬伤后的免疫称为暴露后处理。一、暴露前免疫1、暴露前免疫的优点保护高暴露风险的职业人群。在狂犬病高发地区,如果有足够的疫苗供应,可以建议儿童接受暴露前免疫而获得抗体保护;那…