首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 62 毫秒
1.
Knowledge of the dose-response relation of inactivated vaccines and of the factors that influence this relation is essential for the evaluation of existing vaccine potency assays and the development of new potency assays that are based on the antigen content of the inactivated vaccines. We quantified the relation between vaccine dose, serologic response, and clinical protection after vaccination for three different inactivated Newcastle disease (ND) vaccines. Qualitatively, similar dose-response curves were obtained for the three vaccines when either the serologic response or the clinical protection of specific-pathogen-free (SPF) chickens was plotted against the different vaccine doses applied. However, the vaccines differed quantitatively: doses of vaccines that induced similar antibody titers or clinical protection differed 2-8-fold. In contrast with the narrow range of antibody titers induced by a full vaccine dose, a very broad range of titers was obtained after dilution of the vaccines. At least 95% of the SPF chickens with detectable antibody in the serum were protected against a challenge with virulent Herts ND virus. The relation between the dosage of two different ND vaccines and the serum antibody titers remained markedly constant between 3 and 18 wk after vaccination. Vaccination of broilers instead of layers with a dilution series of inactivated ND vaccine resulted in significantly lower antibody levels and less clinical protection against virulent challenge. In conclusion, despite quantitative differences, we found comparable dose-response relations for the three inactivated ND vaccines studied.  相似文献   

2.
To evaluate the immune response induced by Japanese rabies vaccine for veterinary use as international units (IU), we measured levels of rabies antibody in serum samples from dogs by the rapid fluorescent focus inhibition test (RFFIT). In dogs immunized with a reference vaccine (potency level of 3.1 IU/ml), prepared by the same method as that used to produce commercial vaccine, and its dilutions (1 : 2 or 1 : 4), neutralizing-antibody levels increased to 1.0-2.0 IU/ml over a period of 1 month and then decreased to 0.2-1.5 IU/ml over a period of 1 year after the first vaccination and showed a remarkable increase to 12-47 IU/ml after the second vaccination. Sixty-five (74.7%) of the 87 serum samples from domestic dogs that were tested were seropositive (> or =0.1 IU/ml). However, the seropositive rate in dogs less than 1-year old at the time of vaccination was low (57.1%), and the antibody levels in these dogs were not sufficiently high for the rabies antibody titre in serum to be maintained for 1-year. Levels of rabies antibody in all serum samples were also measured by the virus neutralizing test (VNT), and a strong correlation (r > 0.95) was found between the results of the RFFIT and those of the VNT.  相似文献   

3.
NIH test was used to verify 12 operation batches of the newly developed inactivated tissue vaccine against rabies. The number of international units per 1 cm3 of vaccine was determined by the volumetric method. The number of international units (I.U.) per 1 cm3 of the newly developed vaccines ranged from 1.08 I.U. to 2.59 I.U. per cm3. The average value of all the 12 batches tested is 1.52 I.U. per cm3. The average value of international units in the vaccination dose for dogs is 4.57. All the tested operation batches of the newly developed vaccines met the activity standard recommended by the World Health Organization for veterinary vaccines of this type.  相似文献   

4.
Ginseng, the dry extract prepared from the Panax ginseng C.A. Mayer-root contain immunomodulators named ginsenosides, which in the pig enhance the antibody response to viral and bacterial antigens. The enhancing effect of ginseng was demonstrated vaccinating pigs against porcine parvovirus (PPV) and Erysipelothrix rhusiopathiae infections, using commercially available vaccines. The potency of the licensed, aluminium hydroxide adjuvanted; vaccines were compared with those supplemented with ginseng. The antibody response to PPV was measured by the haemagglutination inhibition (HI) test whereas the mouse potency test and ELISA evaluated the immune response to E. rhusiopathiae. Antibodies to the 64-66 kDa glycoprotein of the E. rhusiopathiae were demonstrated by immunoblotting. The qualitative antibody responses were evaluated by means of ELISA(s) using monoclonal antibodies to swine IgG1 and IgG2. The addition of 2mg ginseng per vaccine dose, potentiate the antibody response of the commercial vaccines without altering their safety. Significantly higher (P<0.001) antibody titres were achieved to both PPV and to E. rhusiopathiae by the supplementation with ginseng. Aluminium hydroxide adjuvanted vaccines favoured the production of IgG1 antibodies. Interestingly, the vaccines supplemented with ginseng favoured IgG2. The vaccines used in the evaluations varied in their immunogenic potency. However, after the addition of ginseng the less immunogenic vaccine proved to be as potent as the better one without ginseng. Thus, the use of ginseng as a co-adjuvant provides a simple, safe and cheap alternative for improving the potency of aluminium hydroxide adjuvanted vaccines.  相似文献   

5.
Groups of three-week-old chickens were given graded doses of inactivated canine parvovirus vaccines. Blood samples were taken three weeks later and the sera examined by ELISA for antibodies to canine parvovirus. Reproducible, linear, log-dose serological responses were observed, enabling the potency of the vaccines to be compared. The simultaneous administration of other components of canine multivalent vaccines appeared to reduce the response to the parvovirus component. When its results have been correlated with the degree of protection in dogs this test could be used to assess the potency of inactivated canine parvovirus vaccines.  相似文献   

6.
Rabies is a neglected disease with an estimated annual mortality of 55,000 human deaths, affecting mainly low-income countries. Over 95% of these cases result from virus transmission through the bite of infected dogs and for this reason there is a real need for a cheap and effective rabies veterinary vaccine to be used in mass vaccination campaigns. In this work, we describe the establishment of a simple platform for the production of a virus-like particles based rabies vaccine using mammalian cells and roller bottles as culture system. Adherent cells were cultured during more than 15 days and VLPs were continuously produced and secreted to the culture supernatant. Immunogenicity and protective efficacy of VLPs were tested through rabies virus neutralizing antibody test and NIH potency test. These viral particles induced high titer of long lasting neutralizing antibodies and protected mice against active virus challenge. Therefore, this development represents a promising platform for the production of a new generation and virus-free rabies vaccine candidate for veterinary applications.  相似文献   

7.
Thirty laboratory dogs were randomly assigned to two groups (A and B) of 15 dogs and subcutaneously vaccinated with a single dose of one of two commercially available monovalent inactivated rabies vaccines: RABISIN (Merial, France) (group A) and NOBIVAC Rabies (Intervet International) (group B). Rabies antibodies were measured over a period of 4 months using the fluorescent antibody virus neutralization (FAVN) test. The two vaccines performed differently in terms of magnitude and persistence of rabies antibodies titers in dogs. Two weeks after vaccination, average rabies antibody titers peaked at 2.53 IU/mL (range, 0.17-13.77 IU/mL) and 1.26 IU/mL (range, 0.50-4.56 IU/mL) in groups A and B dogs, respectively. The average FAVN antibody titres against rabies on D28, D56, D84, D112 and D120 were significantly higher in group A than in group B. Although all dogs from group B serologically responded to vaccination, the proportion of dogs with antibody titres >or=0.5 IU/mL dropped significantly after D28 and was statistically significantly lower on D56, D84 and D112 compared to group A dogs. In conclusion, in the context of international trade, the choice of the vaccine and the timing of blood tests are critical factors in achieving successful serological test results after rabies vaccination. RABISIN induces high and sustained antibody titres against rabies, increasing the flexibility for the time of blood sampling after primo-vaccination.  相似文献   

8.
为了提高猪繁殖与呼吸综合征病毒(PRRSV)ORF5基因DNA疫苗的免疫效力，将通用型辅助性T淋巴细胞表位(PADRE)插入ORF5的中和表位和覆盖表位间，获得修饰后的ORF5基因ORF5M。在此基础上，进一步构建了ORF5M的真核表达质粒pCl-52M。间接免疫荧光证实体外表达后，免疫BALB／c小鼠，检测免疫后的ELISA抗体和中和抗体，并与未经修饰的ORF5基因真核表达质粒pCl-52进行比较。结果表明，修饰后的DNA疫苗pCl-52M诱导的ELISA抗体和中和抗体均明显优于未经修饰的DNA疫苗pCl-52，是一种具有良好开发前景的PRRS新型疫苗。  相似文献   

9.
In this study, we investigated whether Cedivac-FMD, an emergency vaccine against foot-and-mouth disease (FMD), is suitable for use conjointly with a screening program intended to confirm freedom from disease in vaccinated herds based on evidence of virus replication in vaccinates. Different sets of sera were tested using the Ceditest FMDV-NS ELISA for the detection of antibodies against non-structural proteins (NSPs) of FMD virus. During a vaccine safety study, serum samples were collected from 10 calves, 10 lambs and 10 piglets following administration of a double dose and a repeat dose of high payload trivalent Cedivac-FMD vaccine. All serum samples collected both 2 weeks following the administration of a double dose as well as those collected 2 weeks after the single dose booster (given 2 weeks after the double dose) were negative in the Ceditest FMDV-NS ELISA. In a series of vaccine potency experiments, serum samples were collected from 70 vaccinated cattle prior to and following exposure to infectious, homologous FMD virus. When testing cattle sera collected 4 weeks after vaccination with a regular dose of monovalent >6 PD(50) vaccines, 1 of 70 animals tested positive in the NSP antibody ELISA. After infection with FMD virus, antibodies to NSP were detected in 59 of 70 vaccinated cattle and 27 of 28 non-vaccinated control animals within 7 days. Cedivac-FMD vaccines do not induce NSP antibodies in cattle, pigs or sheep following administration of a double dose or a repeat dose. FMD-exposed animals can be detected in a vaccinated group within 7-14 days. Because Cedivac-FMD does not induce NSP antibodies, the principle of 'marker vaccine' applies.  相似文献   

10.
The performance of live, attenuated, homologous, canine parvovirus vaccines was studied in 140 puppies aged from four to 11 weeks. In the presence of maternally derived antibody the ability of the vaccines to elicit a serological response, as determined by the haemagglutination inhibition test and a standardised ELISA, was found to be dose (infectious titre) related. An experimental vaccine containing 10(7.0) TCID50 of virus induced seroconversion rates of 95, 89, 82 and 44 per cent in dogs with haemagglutination inhibition antibody titres of less than or equal to 8, 16, 32 and greater than 32, respectively. The standardised ELISA appeared to be better than the haemagglutination inhibition test with respect to variability and subjectivity, especially when titres were low.  相似文献   

11.
A commercial reovirus vaccine alone or experimental reovirus vaccine plus antibody complex were inoculated into 18-day-old specific pathogen free (SPF) broiler embryos at 0.1 of the recommended chick dose. The following groups were used: group 1A was not vaccinated or challenged; group 1B was not vaccinated, but was challenged with virulent reovirus; group 2 received the vaccine complexed with 1/4 dilution of antiserum; group 3 received the vaccine with 1/8 dilution of antiserum; group 4 received the vaccine with 1/16 dilution of antiserum, and group 5 received vaccine alone. At 1, 3, 6, 9, and 12 days of age, serum was collected and antibody against avian reovirus was analyzed by enzyme-linked immunosorbent assay (ELISA). At the same times, spleens were collected and vaccine virus detected by inoculating chicken embryo fibroblasts (CEFs) and examining for cytopathic effect. At 15 days of age, chickens in groups 2-5 were challenged with reovirus. At 22 days of age, birds were euthanatized and weighed. Efficacy of the vaccines was based on safety, percent protection, and antibody response. In ovo vaccination with the commercial or experimental vaccines did not adversely affect hatchability of SPF chickens. The vaccine complexed with antibody resulted in significantly less posthatch mortality (3.7%) when compared to mortality of chickens that received vaccine alone (17%). Both vaccine virus recovery and antibody response were delayed at least 3 days in birds receiving the experimental vaccines. In evo administration of reovirus antibody complex vaccines provided at least 70% protection. The experimental reovirus-antibody complex vaccines were safe and efficacious when given in ovo to SPF broiler embryos.  相似文献   

12.
We present a comparison of methods for evaluating the potency of foot and mouth disease vaccine in the laboratory. The anti-FMDV antibodies (Ab) in vaccinated mice were tested by liquid phase (lp) ELISA, solid phase (sp) ELISA and virus neutralization (VN), and were compared with the Ab titres detected by lpELISA, which is the official test in Argentina for testing the potency of FMD vaccines and protection against a virulent challenge in cattle. The results demonstrated that it is possible to relate the Ab levels induced in vaccinated mice with both the Ab and protective responses elicited in cattle. Furthermore, it was found that the anti-FMDV Ab titres in mice detected by lpELISA 14 days after vaccination should be an accurate parameter for predicting the results of the challenge test in cattle. Thus, this test in mice appears to be an inexpensive and rapid alternative for testing FMD vaccines in cattle.  相似文献   

13.
OBJECTIVE: To evaluate the effect of various routes of administration and number of doses of 3 commercially produced rabies vaccines on serum antibody responses and protection in mice challenged by intracerebral injection with fixed-strain rabies virus. ANIMALS: 2,213 mice. PROCEDURE: Inactivated, adjuvanted rabies vaccines were administered to mice in either 2, 1, or 0 (control) doses via IP, IM, and SC routes, and mice were challenged intracerebrally with fixed-strain rabies virus. RESULTS: Vaccination route and dose number significantly influenced serum antibody responses and protection from rabies virus challenge, independent of vaccine strain origin and mouse strain, although mouse age significantly affected results. Extended challenge studies revealed that IM vaccination of mice resulted in the highest serum neutralizing antibody responses and protection levels equivalent to IP vaccination. Even multiple doses administered SC (a vaccination route used in dogs) resulted in poor serum anti-rabies neutralizing antibody responses in mice and were far less protective than other routes. CONCLUSIONS AND CLINICAL RELEVANCE: Findings suggest possible improvements for the current rabies vaccine potency test in mice by using 1 dose, the IM route, and a delayed time of challenge. These modifications would more closely model vaccination practices in target species and yield more accurate information regarding primary immunogenicity of a vaccine.  相似文献   

14.
分别用犬细小病毒（CPV）核酸疫苗（pVCPV-VP2）、CPV重组活载体疫苗（CAV2／CPV）与CPV弱毒疫苗对犬进行了免疫试验,以检测不同CPV疫苗的免疫原性。采用CPVELISA、CPVHI与CPV微量中和试验检测免疫犬的体液免疫水平,采用淋巴细胞转化试验检测犬的细胞免疫水平。结果,pVCPV—VP2和CAV2／CPV均能诱导机体产生抗CPVELISA抗体与抗CPV中和抗体,但是pVCPV-VP2不能诱导机体产生可检测的抗CPVHI抗体,而CAV2／CPV能够诱导机体产生抗CPVHI抗体。淋巴细胞转化试验结果,pVCPV-VP2和CAV2／CPV免疫犬的外周血淋巴细胞对ConA与CPV的刺激均出现明显的增殖反应。结果表明,pVCPV—VP2和CAV2／CPV免疫犬均能诱导机体产生抗CPV的特异性体液免疫反应和细胞免疫反应,两者所表达的VP2蛋白均具有较好的免疫原性。CAV2／CPV以及pVCPV—VP2和CAV2／CPV联合免疫犬的抗CPV体液免疫水平和细胞免疫水平均比用pVCPV—VP2单独免疫犬的体液免疫水平和细胞免疫水平高。但CAV2／CPV诱导机体产生的抗CPV特异性免疫反应仍然比CPV弱毒疫苗诱导机体产生的抗CPV特异性免疫反应弱。另外,CAV2／CPV还能诱导机体产生抗CAV-2的特异性免疫反应。  相似文献   

15.
The potency of inactivated Newcastle disease virus (NDV) vaccines in the United States is currently determined using vaccination and challenge of experimental animals against a velogenic strain of NDV. Because velogenic strains of NDV are now classified as select agents in the United States, all vaccine potency testing must be performed in live animals under biosafety level 3 agriculture conditions. If the minimum amount of inactivated viral antigen required for clinical protection can be determined using other methods, vaccines meeting these criteria might be considered of adequate potency. The linearity of correlation between the hemagglutination (HA) assay measurement and the 50% embryo infectious dose titer ofNDV Hitchner B1 vaccine virus was determined. Correlation between hemagglutinin units (HAU) per vaccine dose, clinical protection, and antibody response was then determined using a vaccinate-and-challenge model similar to Chapter 9 of the U.S. code of federal regulations approved method for vaccine potency testing. The dose providing 50% protection of an in-house water-in-oil emulsion vaccine formulated with inactivated NDV B1 was determined to be between 400 and 600 HAU from two separate trials. A positive correlation (R2 = 0.97) was observed between antibody response and HAU per vaccine dose. Serum antibody responses from vaccinated birds indicate HA inhibition titers >2(5) log2 would provide 100% protection from morbidity and mortality and require a minimum protective dose of 1000 HAU per bird. These are the first studies to examine establishing both a minimum protective HAU content for inactivated ND vaccines and a minimum serologic response necessary to ensure potency.  相似文献   

16.
A comparative study was undertaken on the immunogen power of autoclaved Leishmania major promastigotes (ALM) vaccines given simultaneously with either BCG or saponin against canine leishmaniasis. The humoral immune response was assessed by ELISA and western blotting. The cellular immune response was evaluated by the lymphocyte transformation test. Dogs vaccinated simultaneously with ALM and saponin showed high antibody titres to crude L. infantum antigens after the first vaccine booster and reacted with several antigens, with molecular weights from 26 to 108 kDa by western blotting. However, the lymphocyte proliferation of these dogs to the crude L. infantum antigen was not significantly different from the control group. In contrast, in dogs vaccinated simultaneously with ALM and BCG, the antibody titres to crude antigen were low. Their sera reacted with the same proteins recognised by sera from dogs vaccinated simultaneously with ALM and saponin by western blotting. However, the 85-kDa protein was only identified by sera taken from dogs vaccinated simultaneously with ALM and BCG. These latter exhibited specific lymphocyte proliferation to the L. infantum antigen. This cell proliferation was observed for approximately 9 months after the first dose of the vaccine. This study indicates that a combination of ALM as the vaccine and BCG as the adjuvant, in the dog model, was successful in inducing a cell immune response, which is implicated in protection of dogs against a Leishmania infection.  相似文献   

17.

Background

United Kingdom, Ireland, Malta and Sweden maintain their national provisions for a transitional period regarding rules concerning rabies vaccination and individual serological test for rabies neutralizing antibodies. The purpose of vaccinating dogs against rabies is to establish pre-exposure immunity and protect individual animals from contracting rabies.The aim of the study was to investigate factors associated with reaching the internationally accepted threshold antibody titre of 0.5 IU/mL after rabies vaccination of dogs.

Methods

The study was a prospective single cohort study including 6,789 samples from Swedish dogs vaccinated with commercially available vaccines in Sweden, and the dog''s antibody responses were determined by the OIE approved FAVN test. Information on potential risk factors; breed, age, gender, date of vaccination, vaccine label and the number of vaccinations, was collected for each dog. Associations between the dependent variable, serological response ≥ 0.5 IU/mL or < 0.5 IU/mL and each of the potential risk factors were investigated using logistic regression analysis.

Results

Of 6,789 vaccinated dogs, 6,241 (91.9%) had an approved test result of ≥ 0.5 IU/mL. The results of the multivariable logistic regression analysis showed that vaccinating with vaccine B reduced the risk of having antibody titres of < 0.5 IU/mL by 0.2 times compared with vaccination using vaccine A. Breed size was found significant as an interaction with number of vaccinations and age at vaccination as an interaction with day of antibody testing after last vaccination. In summary, larger breeds were at higher risk of having antibody titres of < 0.5 IU/mL but if vaccinated twice this risk was reduced. Moreover, there were a increased risk for dogs < 6 months of age and > 5 years of age to have antibody titres of < 0.5 IU/mL, but this was affected by number of days from vaccination till testing.

Conclusions

The probability of success of rabies vaccinations of dogs depends on type of vaccine used, number of rabies vaccinations, the breed size of the dog, age at vaccination, and number of days after vaccination when the antibody titres are tested. The need for a booster vaccination regimen is recommended for larger breeds of dog.  相似文献   

18.
The immunogenicity of a sonicated extract (SE) and of outer membrane proteins (OMP) of Salmonella enteritidis was tested in birds of about 8 weeks of age. The dose, route of vaccination and the adjuvant used varied in different groups of birds. Two vaccine doses with or without adjuvant were given parenterally or orally 3 weeks apart. OMP vaccines gave significantly higher antibody titres than SE vaccines, as indicated by ELISA. The vaccines adjuvanted with oil produced higher antibody titres than those without any adjuvant. A dose of 1 mg of vaccine produced higher antibody titres than 0.5 mg of vaccine. Adjuvanted vaccine given subcutaneously elicited higher antibody responses than oral vaccines given without adjuvant. The birds were challenged with virulent S. enteritidis organisms at the end of the second week after a booster dose. None of the birds given 1 mg of OMP vaccine subcutaneously shed the organisms when tested by culturing cloacal swabs, although a few birds vaccinated with 0.5 mg of OMP vaccine did so. In general, adjuvanted OMP vaccines gave better protection than SE vaccines.  相似文献   

19.
Summary

The significance of canine parvovirus (CPV) infections as a permanent threat to susceptible dogs, in particular pups, made the authors develop three liquid homologous inactivated adjuvant CPV vaccines that were compatible with existing canine vaccines and could he incorporated in current vaccination programmes. One vaccine (Kavak Parvo) contained only the CPV component, the second product (Kavak i‐LP) also contained two inactivated leptospiral antigens, and the third vaccine (Kavak i‐HLP) contained in addition an inactivated canine hepatitis virus.

This paper reports on the studies conducted to test the safety and efficacy of the three products. They were used as such and as diluents for freeze dried vaccines containing live attenuated measles, distemper, and hepatitis viruses. The study was performed in a breeding kennel where all dogs were free from CPV antibodies and the nonvaccinated sentinels remained so for the course of the study. All vaccines proved to be safe in dogs of all ages, including pregnant bitches. The efficacy of the CPV component was studied both by monitoring antibody titres for more than a year and by challenge exposure of some dogs to virulent CPV. The results obtained from these studies prove that the CPV component used in the three vaccines can be incorporated as indicated in the recommended canine vaccination programmes. The observations that both the inactivated CPV and hepatitis components do induce an active immunity in pups that are still protected by low levels of maternally derived antibodies against these viruses, make those vaccines very suitable in breeding kennels. Additional studies on a comparative basis are being continued in endemically CPV infected breeding kennels to quantify the significance of these observations in these special conditions.  相似文献   

20.
Inactivated, nonadjuvanted tissue culture-origin rabies vaccine was tested in 168 dogs for its ability to provide protection against challenge of immunity 1 year after vaccination. Several laboratory methods were used concurrently to measure the potency of the vaccine. When used at full strength, the vaccine protected 70% of dogs after either a 1- or 2-dose vaccination schedule. When vaccine was diluted to contain less antigenic mass, the 1-dose schedule was not as effective as 2 doses. High serum-neutralizing antibody titers developed by 7 days after vaccination, but the titers declined rapidly thereafter. The US reference vaccine protected 28 of 30 dogs.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号