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1.
The serological response of foals to vaccination against strangles.   总被引：3，自引：1，他引：2       下载免费PDF全文
A group of 100 foals was given either a commercial bacterin or an autogenous vaccine consisting of whole cells and an acid extract of Streptococcus equi. During the study, some of the foals developed clinical strangles. Various sets of sera were collected from these foals prevaccination, during vaccination, postvaccination and postinfection. The serological response of these foals was measured by passive haemagglutination and long chain tests. In foals which remained healthy, the highest titres were reached within one to two months postvaccination with a passive haemagglutination 10 x log2 mean titre of 6.78 and the long chain indices of 4.41. These levels persisted for 120 days postvaccination. Those foals which had clinical strangles exhibited lower passive haemagglutination titres (3.78) at one to two months postimmunization, but rose significantly after recovery. Four ponies immunized with formalinized Str. equi bacterin showed a partial protection against the challenge infection. The passive haemagglutination titres, long chain indices and serum bactericidal activity in these ponies were highest at 35 days postvaccination but did not increase after infection.  相似文献   

2.
As part of a search for a safe and efficacious strangles vaccine, several different vaccines and different vaccination routes were tested in foals. The degree of protection was evaluated after an intranasal challenge with virulent Streptococcus equi by clinical, postmortem and bacteriological examinations. Inactivated vaccines containing either native purified M-protein (500 microg per dose) or whole S equi cells (10(10) cells per dose) administered at least twice intramuscularly at intervals of four weeks, did not protect against challenge. Different live attenuated S equi mutants administered at least twice at intervals of four weeks by the intranasal route were either safe but not protective or caused strangles. In contrast, a live attenuated deletion mutant administered intramuscularly, induced complete protection but also induced unacceptable local reactions at the site of vaccination. Submucosal vaccination in the inner side of the upper lip with the live attenuated mutant at > or =10(8) colony-forming units per dose, appeared to be safe and efficacious in foals as young as four months of age. The submucosal vaccinations caused small transient swellings that resolved completely within two weeks, and postmortem no vaccine remnants or other abnormalities were found at the site of vaccination.  相似文献   

3.
Adult houbara bustards (Chlamydotis undulata) and juvenile kori bustards (Ardeotis kori) were given four regimens of commercially available inactivated and live poultry paramyxovirus type 1 (PMV-1) vaccines. Immunologic response to vaccination was assessed by hemagglutination inhibition assay of serum. Kori bustards, to which a dose of 0.5 ml of a commercially available inactivated vaccine for poultry had been administered intramuscularly (0.15 ml/kg body weight), failed to develop hemagglutinating antibodies, but antibody titers of low intensity and duration were detected following administration of a second and third subcutaneous dose of 2.0 ml vaccine per bird (0.40-0.45 ml/kg). In subsequent trials, when inactivated vaccine was administered subcutaneously at 1.0 ml/kg body weight following two or four live vaccinations administered by the ocular route, juvenile kori bustards developed higher, more persistent titers of antibodies. Kori bustards given four live vaccinations followed by inactivated vaccine developed higher titers of longer duration compared with kori bustards given two live vaccines followed by inactivated vaccine. Antibody titers of kori bustards given inactivated vaccine were higher and more persistent than the antibody response to live vaccination. Houbara bustards, previously vaccinated with inactivated vaccine, that were given a booster dose of inactivated vaccine maintained high mean antibody titers (> or = log, 5) for 52 wk. The authors recommend that inactivated PMV-1 vaccine should be administered by subcutaneous injection of 1.0 ml/kg vaccine to bustards. Adult bustards, previously vaccinated with inactivated vaccine, should be vaccinated annually with inactivated vaccine. Juvenile bustards should receive a second dose of inactivated vaccine 4-6 mo after the first dose of inactivated vaccine. Even though inactivated PMV-1 vaccines induced hemagglutination inhibition antibodies and produced no adverse reactions, further studies will be required to determine the protective efficacy of the antibody.  相似文献   

4.
Avridine, a lipoidal amine with interferon-inducing and adjuvant properties, was an effective adjuvant for Newcastle disease antigen (NDA) in chickens. Eleven vaccine lots were evaluated: 2 commercial water-in-oil vaccines, 4 experimental oil emulsion vaccines, 4 avridine-containing vaccines, and a control lot of nonadjuvanted antigen. Avridine significantly enhanced the immunologic responses of chickens against NDA. Chickens vaccinated with the avridine-containing vaccines had significantly higher antibody titers (hemagglutination inhibition) than did chickens vaccinated with the commercial vaccines. Experimental oil emulsion vaccines prepared from the same antigens as avridine-adjuvanted vaccines induced higher hemagglutination inhibition antibody titers after primary but not after booster vaccination. Use of avridine as an adjuvant for NDA in vaccines for chickens induced immunologic protection rates similar to those induced by oil emulsion vaccines, without causing the reactogenic and tissue residue problems associated with the use of oil vaccines in chickens.  相似文献   

5.
An indirect test based on horse blood was used to study bactericidal responses of the horse to Streptococcus equi following infection or vaccination. Bactericidal antibody appeared in convalescent sera between two and four weeks and high titres were usually attained by eight weeks. Infection without clinical evidence of abscessation was also effective in eliciting strong bactericidal responses. Serum bactericidal activity of horses either recovered from strangles or immunised with commercial bacterin had declined eight months after vaccination. However, horses that developed strangles eight to 10 months after vaccination exhibited rapid and substantial increases in serum bactericidal activity. Groups of yearlings immunised with commercial S equi vaccines consisting either of M protein or bacterin developed clinical strangles within six months of vaccination although the majority of the animals had exhibited strong serum bactericidal activity a few weeks before occurrence of the disease. Similarly, a group of seven yearling ponies hyperimmunised with experimental vaccine, rich in M protein, were found to be highly susceptible to an intranasal challenge of 5 X 10(8) colony forming units of S equi, although their sera exhibited strong bactericidal activity at the time of challenge. These observations suggest that the role of serum bactericidal antibody in protection of the horse against strangles has been overrated.  相似文献   

6.
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.  相似文献   

7.
Turkeys given cell-free culture filtrate (CCF) of Pasteurella multocida strain R44/6 orally, via air sacs, or subcutaneously mixed 1:1 with incomplete Freund's adjuvant (IFA) at 6 and 9.5 weeks of age were compared with negative controls given bacteriologic medium and positive controls vaccinated with a commercial bacterin. At 13 weeks of age, serum antibody titers to P. multocida were detectable only in turkeys given CCF in IFA (low titers) and positive control turkeys (high titers), at which time turkeys were challenged orally with either the homologous strain or strain P-1059. Protection against challenge with strain R44/6 was provided by the commercial bacterin, CCF in IFA, and CCF given via air sacs. When turkeys were challenged with strain P-1059, protection was superior in turkeys given CCF via air sacs, intermediate in turkeys given commercial bacterin or CCF in IFA, and absent in negative control turkeys and turkeys given CCF orally. These results indicate CCF is an effective immunogen when administered via the lower respiratory tract for protecting turkeys against pasteurellosis.  相似文献   

8.
Transformation of peripheral blood lymphocytes from pony foals vaccinated and subsequently infected with Corynebacterium equi was studied. Three foals were vaccinated on two occasions using a formalinized C. equi vaccine with aluminum hydroxide as an adjuvant. Three nonvaccinated foals served as controls. Foals were challenged intratracheally with 9 x 10(9) C. equi six weeks after the initial vaccination.Foals survived this infection for one to two weeks. Significant lymphocyte transformation in response to C. equi antigens was detected in two vaccinated foals at the third week after initial vaccination and in all vaccinated animals at the fifth week. No statistically significant transformation was seen in nonvaccinated foals before infection. Vaccinated and nonvaccinated foals showed responsive lymphocytes following challenge. Vaccination offered no obvious protection against experimental challenge but this failure was probably due to an excessive infective dose of organisms. Low levels of humoral antibodies were detected in some challenged foals. The pathological changes in the lungs of infected animals were comparable with, but more fulminating than, changes observed in the natural disease.  相似文献   

9.
An experiment was conducted to determine the efficacy of an autogenous bacterin against infectious coryza from a local strain of Haemophilus paragallinarum in Morocco compared with a commercial vaccine. Hens were vaccinated with a single dose or two doses of the bacterin at 15 and 18 weeks of age. Both the autogenous and the commercial vaccine conferred significant protection against experimental challenge (94% and 88%, respectively). A single dose was less protective with both vaccines.  相似文献   

10.
We compared the efficacy of 3 commercial vaccines against swine influenza A virus (SIV) and an experimental homologous vaccine in young pigs that were subsequently challenged with a variant H3N2 SIV, A/Swine/Colorado/00294/2004, selected from a repository of serologically and genetically characterized H3N2 SIV isolates obtained from recent cases of swine respiratory disease. The experimental vaccine was prepared from the challenge virus. Four groups of 8 pigs each were vaccinated intramuscularly at both 4 and 6 wk of age with commercial or homologous vaccine. Two weeks after the 2nd vaccination, those 32 pigs and 8 nonvaccinated pigs were inoculated with the challenge virus by the deep intranasal route. Another 4 pigs served as nonvaccinated, nonchallenged controls. The serum antibody responses differed markedly between groups. After the 1st vaccination, the recipients of the homologous vaccine had hemagglutination inhibition (HI) titers of 1:640 to 1:2560 against the challenge (homologous) virus. In contrast, even after 2nd vaccination, the commercial-vaccine recipients had low titers or no detectable antibody against the challenge (heterologous) virus. After the 2nd vaccination, all the groups had high titers of antibody to the reference H3N2 virus A/Swine/Texas/4199-2/98. Vaccination reduced clinical signs and lung lesion scores; however, virus was isolated 1 to 5 d after challenge from the nasal swabs of most of the pigs vaccinated with a commercial product but from none of the pigs vaccinated with the experimental product. The efficacy of the commercial vaccines may need to be improved to provide sufficient protection against emerging H3N2 variants.  相似文献   

11.
The nasal and serum antibody response of two groups of pigs, vaccinated with adjuvant containing formalinized or sonicated Bordetella bronchiseptica bacterins was compared with the response of a nonvaccinated group. The tube agglutination test was used to determine agglutinin titers. Following vaccination, all pigs were challenged intranasally with the vaccine strain of Bordetella, after which the nasal Bordetella flora of vaccinated and nonvaccinated pigs was investigated. Sera and nasal secretions from both vaccinated groups exhibited markedly higher agglutinin titers than the control group and serum titers were higher than those in nasal secretions. No differences in agglutinating antibody response were evident between the two vaccines. Serum antibody titers exceeded nasal titers and persisted over a longer period of time. Systemic vaccination resulted in an increased nasal clearance of the vaccine strain by the groups of pigs vaccinated with sonicated or formalined bacterin, whereas no such clearance was evident in the nonvaccinated control group.  相似文献   

12.
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   

13.
Broiler minibreeder hens were vaccinated for protection against fowl cholera at 12 and 21 weeks of age using several vaccination schemes, which included a live Pasteurella multocida (CU strain) vaccine, two commercial polyvalent fowl cholera oil-based bacterins, and two experimentally prepared polyvalent oil-based bacterins. Some treatment groups received only live or killed vaccines, whereas others received a live vaccine at 12 weeks followed by a killed product at 21 weeks. At 42 weeks of age, all birds that received the live CU vaccine twice or once followed by a bacterin survived challenge. Birds that received killed vaccines only were significantly less protected but still showed a respectable survival rate of 86%. All unvaccinated controls died within 72 hr after challenge. At 72 weeks of age, overall protection was lower than that at 42 weeks, regardless of vaccination treatment. Antibody titers were usually higher in birds that received bacterins than in those receiving live vaccines, yet overall protection was still greater in those birds that received the live cholera vaccine twice.  相似文献   

14.
A double-blind randomized clinical trial was undertaken to determine the value of parenterally administered Streptococcus equi M-protein vaccine in foals during an epizootic of strangles. Weaned mixed-breed foals (n = 664) housed on 2 adjacent feed-lots (A and B) arrived over a 5-day period, 2 weeks before primary vaccination. Foals in lot B (n = 114) were randomly administered vaccine (n = 59) or saline solution (placebo; n = 55) on 3 occasions at biweekly intervals. Foals in lot A (n = 450) were given 1 dose of vaccine (n = 225) or placebo. The following clinical observations were scored blindly by a single observer for all foals in lot B and for 120 (randomly sampled) foals in lot A on a single day, 2 (Lot B) and 6 (lot A) weeks after final vaccination: cervical lymphadenopathy, type of bilateral nasal discharge, and palpable swelling at injection site(s). Bacteriologic culture of nasal swab specimens or lymph node aspirates from selected foals with clinical disease yielded S equi. Cervical lymphadenopathy was observed in 17 of 59 (29%) vaccinates and 39 of 55 (71%) nonvaccinated controls in lot B and in 32 of 60 (53%) vaccinates and 29 of 60 (48%) controls in lot A. Contingency chi 2 analysis confirmed significantly lower cervical lymphadenopathy rate (chi 2 = 18.5; P less than 0.001) and prevalence of mucopurulent nasal discharge (chi 2 = 11.4; P less than 0.01) for vaccinates in lot B only. Swelling(s) at the vaccine injection site were palpated in 44% of lot B and 29% of lot A vaccinates vs less than 2% of placebo controls.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

15.
Rhodococcus equi produces two exoenzymes (REE), a cholesterol oxidase in large amounts and a phospholipase C, which cause lysis of sheep red blood cells (SRBC) sensitized with Staphylococcus aureus beta toxin. Two immunization studies were done in foals to determine the role of antibody to REE in protection against R. equi pneumonia. In the first study, three foals (mean age 10 days) were vaccinated four times at 2-week intervals with over 1 million units of partially purified exoenzymes (PREE). In the second study, three foals (mean age 19 days) were administered plasma from an adult horse vaccinated with PREE. Relatively low titres (16-32) of neutralizing antibody were detected in the foals of the former group, and passive transfer of neutralizing antibody (titres 32-64) occurred in the latter. Following immunization, principal foals and an equal number of similarly aged nonimmunized foals were challenged by aerosol with 1 x 10(10) live R. equi per day for 5 consecutive days. No severe clinical pneumonia developed in either group and, with one exception, only minor and resolving lung abscesses developed in these foals. These studies showed that antibody response of foals to immunization with PREE was poor, antibody to PREE did not prevent foals from developing lung abscesses following experimental infection, and that foals even as young as 3 weeks of age may be largely refractory to aerosol challenge with virulent R. equi.  相似文献   

16.
Cattle were vaccinated against leptospirosis with 3 bacterin preparations: (a) trivalent (serotypes grippotyphosa, pomona, and hardjo) whole cell bacterin; (b) bivalent pomona and hardjo whole cell bacterin; and (c) pentavalent (canicola, grippotyphosa, icterohaemorrhagiae, pomona, and hardjo) cell wall bacterin. Microscopic agglutinating antibody responses in cattle given the last-named bacterin were higher than those in cattle vaccinated with the 2 whole cell bacterins (trivalent and bivalent). However, microscopic agglutinating antibody responses occurred in all vaccinated cattle after they were given a challenge inoculation of serotype hardjo. Leptospires were isolated from 2 of 4 challenge controls (i.e., not given any bacterin), but none of the 15 vaccinated cattle given any one of the bacterins and then challenge inoculated with hardjo became culturally positive. It was concluded that the 3 multivalent bacterins were protective against experimental challenge inoculation of hardjo.  相似文献   

17.
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.  相似文献   

18.
A commercial enzyme-linked immunosorbent assay (ELISA) to detect serological response to vaccination and virulent challenge with type 1 (X-73) Pasteurella multocida was used to determine the best vaccination protocol for broiler breeders against fowl cholera. Birds vaccinated twice, at 10 and 19 weeks of age, with the avirulent Clemson University (CU) strain both times, with a commercial bacterin first and the CU strain second, or with the CU strain first and bacterin second had the highest survival rates (98-100%) following challenge at 25 weeks. The two groups that received the CU strain and bacterin also produced the highest mean ELISA antibody titers (greater than 10,000). Birds vaccinated once, at 10 weeks, with the CU strain had the same survival rate as birds vaccinated twice with bacterin (90 and 91%). Under the conditions of this experiment, an ELISA titer greater than or equal to 1000 resulted in at least a 92% survival rate after virulent challenge (23% survival in nonvaccinates).  相似文献   

19.
Antibody responses were compared in guinea-pigs, rabbits and pigs following vaccination with inactivated porcine parvovirus (PPV) vaccines. Mean PPV hemagglutination inhibition (HI) antibody titers of 52, 56 and 36 at 1 week after first vaccination and 896, 640 and 512 at 2 weeks after second vaccination were detected in guinea-pigs, rabbits and pigs, respectively. PPV vaccines prepared with greater concentrations of virus, as determined by hemagglutination (HA) units, and of aluminum hydroxide gel adjuvant, induced higher HI antibody titers in guinea-pigs. Optimal concentrations for inducing consistently high antibody titers consisted of vaccine virus with a HA titer of 256/0.1 ml and gel adjuvant at a final concentration of 50%. A second vaccination at 4 weeks compared to 2 or 3 weeks after first vaccination resulted in higher mean HI titers. These data provide preliminary information on the use of guinea-pigs or rabbits as laboratory animal models for testing the potency of PPV vaccines.  相似文献   

20.
The aim of this study was to evaluate serum IgG antibody levels and opsonizing activity in foals from pregnant mares immunized with either proteins from an R. equi strain containing virulence-associated protein A (VapA), an immunodominant surface-expressed lipoprotein encoded by a virulence plasmid crucial for virulence in foals, or a whole killed virulent R. equi preparation. Forty-eight pregnant mares were distributed into three groups, i.e. 24 immunized with R. equi VapA protein antigen associated with a water-based nanoparticle adjuvant (Montanide IMS 3012), 8 immunized with whole killed R. equi, and 16 non-immunized as control. Serum IgG and opsonizing capacity were evaluated during pregnancy in mares, and up to day 45 post-delivery in foals in which R. equi infections were recorded in the first 6 months of life. Pregnant mares immunized with virulent R. equi proteins developed higher serum IgG and opsonic activity which were transferred to the foals than either in the whole R. equi immunized or the control group. Four foals developed pneumonia in the control group while none in immunized groups. Results support further evaluation of VapA protein antigen associated with a water-based nanoparticle adjuvant as a candidate vaccine for immunization of pregnant mares resulting in passive antibody-mediated protection of foals.  相似文献   

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