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Eight puppies (group 1) were vaccinated once with a bivalent modified-live vaccine against infectious tracheobronchitis by the intranasal route and at the same time with an injectable trivalent vaccine against canine parvovirus, canine distemper virus and canine adenovirus; a second group of eight puppies (group 2) was vaccinated only with the intranasal bivalent vaccine, and a further eight puppies (group 3) were vaccinated only with the injectable trivalent vaccine. Three weeks later they were all challenged with wildtype Bordetella bronchiseptica and canine parainfluenza virus by the aerosol route, and their antibody responses to the five vaccine organisms were determined. Oronasal swabs were taken regularly before and after the challenge for the isolation of bacteria and viruses, and the puppies were observed for clinical signs for three weeks after the challenge. There were no significant differences in the puppies' titres against canine parvovirus, canine distemper virus and canine adenovirus type 2 between the groups vaccinated with or without the bivalent intranasal vaccine. After the challenge the mean clinical scores of the two groups vaccinated with the intranasal vaccine were nearly 90 per cent lower (P=0.001) than the mean score of the group vaccinated with only the trivalent injectable vaccine, and the puppies in this group all became culture-positive for B bronchiseptica and canine parainfluenza virus. There were only small differences between the rates of isolation of B bronchiseptica from groups 1, 2 and 3, but significantly lower yields of canine parainfluenza virus were isolated from groups 1 and 2 than from group 3.  相似文献   

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A field study was conducted under commercial feedlot conditions at 2 sites in western Canada to determine the relative effects of a univalent viral vaccine (MLV 1) program versus a multivalent viral vaccine (MLV 4) program on animal health; feedlot performance; and carcass characteristic variables of fall-placed, auction market derived, feedlot calves. Five thousand one hundred and sixty-three calves were processed and randomly allocated to 1 of 2 experimental groups as follows: MLV 1, which received a modified live infectious bovine rhinotracheitis (IBR) virus vaccine upon arrival at the feedlot and again at approximately 70 days on feed (DOF); or MLV 4, which received a modified live IBR virus, parainfluenza-3 virus, bovine viral diarrhea virus, and bovine respiratory syncytial virus vaccine upon arrival at the feedlot and again at approximately 70 DOF. A total of 20 pens (10 pens at the site located near High River, Alberta and 10 pens at the site located near Vegreville, Alberta) were allocated to the study. On both a live and carcass weight basis, final weight, weight gain, and average daily gain (ADG) were significantly (P < 0.05) improved in the MLV 4 group as compared with the MLV 1 group. However, there were no significant (P > or = 0.05) differences in DOF, daily dry matter intake, dry matter intake to gain ratio (DM:G) live, or DM:G carcass between the experimental groups. In addition, there were no significant (P > or = 0.05) differences between the experimental groups in any of the carcass characteristic variables measured. The initial undifferentiated fever (UF) treatment rate was significantly (P < 0.05) lower in the MLV 4 group as compared with the MLV 1 group. There were no significant (P > or = 0.05) differences in the other measures of health between the experimental groups. In the economic analysis, there was a net advantage of $0.74 CDN per animal in the MLV 4 group as compared with the MLV 1 group due to lower initial UF treatment and improved ADG, even though the cost of the vaccine program was higher in the MLV 4 group.  相似文献   

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Dogs are the domestic reservoir for Leishmania infantum, the parasite causing zoonotic visceral leishmaniasis (VL) in both the Old and New Worlds. Since the available methods for canine leishmaniasis treatment and control have limited efficacy, the development of a canine Leishmania vaccine is highly desirable. Mechanisms of antileishmanial immune responses in murine, human, and canine infections are briefly presented. Vaccine candidates, including live or killed parasites, Leishmania purified fractions, defined recombinant parasite antigens, live recombinant bacteria expressing Leishmania antigens and antigen-encoding DNA plasmids, are reviewed. Finally, some practical requirements for the evaluation of vaccine candidates in dogs are indicated.  相似文献   

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The various research periods leading to the development of paraspecific vaccines are described. Paraspecific vaccines are new, pyrogen-free, non-toxic preparations that contain non-immunising antigens and can be used to generate endogenic protective, non-antigen specific mechanisms in the sense of paramunization in humans and animals. They consist of highly attenuated and inactivated (0.05% beta-propiolactone) virus strains of various poxvirus genera. They activate the T helper cells and cellular elements of the paraspecific (innate) immune system and initiate the associated production and release of cytokines (cytokine cascade) with the goal of eliminating dysfunctions of the immune systems, rapidly enhancing the individual's non-pathogen- and non-antigen-specific defences and exerting a regulatory effect on the interplay between the immune, hormone, nervous and vascular systems (signal-transduction mediators). They can be used systemically (intramuscularly) and locally (mucous membranes, skin). Immunization with paraspecific vaccines does not lead to postvaccinal complications and can be carried out as often as necessary, even for a number of years. They are compatible with conventional medicines and conventional specific vaccines. Closely linked protein complexes in the envelopes of the virus particles are responsible for their efficacy some of those envelope protein complexes possess the properties of weak super antigens. Paraspecific vaccines have proved effective in combating viral infections, in particular herpes and hepatitis B and C infections, and chronic inflammatory diseases, and also as adjuvant therapy for tumours, for curing stress-related disturbances and dysfunctions of the immune system.  相似文献   

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The safety, efficacy and cross-protectivity of a live intranasal aerosol haemorrhagic septicaemia vaccine containing Pasteurella multocida serotype B:3,4 were tested in young cattle and buffaloes in Myanmar, where more than 1.5 million animals had been inoculated with this vaccine between 1989 and 1999. A recommended dose of 2 x 10(7) viable organisms was used for the efficacy test. The administration of 100 times the recommended dose to 50 cattle and 39 buffalo calves was innocuous. Seven months after they were vaccinated, three of three buffaloes were protected and 12 months after they were vaccinated, three of four buffaloes were protected against a subcutaneous challenge with serotype B:2 which killed three of three unvaccinated buffaloes. Twelve months after they were vaccinated, eight of eight cattle survived a serotype B:2 challenge, which killed four of four unvaccinated controls. The vaccinated cattle had developed serum antibodies detectable by the passive mouse protection test. Indirect haemagglutination tests on sera taken from cattle 10 days and five weeks after they were vaccinated showed high titres of antibodies. The serum of vaccinated cattle cross-protected passively immunised mice against infection with P. multocida serotypes E:2, F:3,4 and A:3,4.  相似文献   

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We evaluated a recently developed live vaccine candidate for fowl typhoid (FT)-JOL916, a lon/cpxR mutant of Salmonella Gallinarum (SG)-by comparing its safety and efficacy with that of the well-known rough mutant strain SG9R vaccine in 6-wk-old Hy-Line hens. Forty-five chickens were divided into three groups of 15 chickens each. The chickens were then intramuscularly inoculated with 2 x 10(7) colony-forming units (CFUs) of JOL916 (JOL916 group), 2 x 10(7) CFUs of SG9R (SG9R group), or phosphate-buffered saline (control group). After vaccination, no clinical symptoms were observed in any of the groups. No differences in body weight increase were detected among the three groups postvaccination. A cellular immune response was observed at 2 wk postvaccination (wpv) in the JOL916 group with the peripheral lymphocyte proliferation assay, whereas no response was detected in the SG9R group. Elevation of SG antigen-specific plasma immunoglobulin was observed 2 and 3 wpv in the JOL916 and SG9R vaccine groups, respectively. After virulent challenge on day 25 postvaccination, 0, 1, and 15 chickens in the JOL916 group, SG9R group, and control group, respectively, died by 12 days postchallenge; the death rate of the SG9R vaccine group was statistically similar to that of the JOL916 group. Postmortem examination revealed that the JOL916 vaccine offered more efficient protection than the SG9R vaccine, with significantly decreased hepatic necrotic foci scores, splenic enlargement scores, necrotic foci scores, and recovery of the challenge strain from the spleen. Vaccination with JOL916 appears to be safe and offers better protection than SG9R against FT in chickens.  相似文献   

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A randomised, controlled, double-blind, influenza virus, aerosol challenge of horses was undertaken to determine the efficacy of a cold-adapted, temperature sensitive, modified-live virus, intranasal, equine influenza vaccine. Ninety 11-month-old influenza-na?ve foals were assigned randomly to 3 groups (20 vaccinates and 10 controls per group) and challenged 5 weeks, 6 and 12 months after a single vaccination. Challenges were performed on Day 0 in a plastic-lined chamber. Between Days 1 and 10, animals were examined daily for evidence of clinical signs of influenza. Nasal swabs for virus isolation were obtained on Day 1 and Days 1 to 8 and blood samples for serology were collected on Days 1, 7 and 14. There was no adverse response to vaccination in any animal. Following challenge at 5 weeks and 6 months, vaccinates had significantly lower clinical scores (P = 0.0001 and 0.005, respectively), experienced smaller increases in rectal temperature (P = 0.0008 and 0.0007, respectively) and shed less virus (P<0.0001 and P = 0.03, respectively) over fewer days (P<0.0001 and P = 0.002, respectively) than did the controls. After the 12 month challenge, rectal temperatures (P = 0.006) as well as the duration (P = 0.03) and concentration of virus shed (P = 0.04) were significantly reduced among vaccinated animals. The results of this study showed that 6 months after a single dose of vaccine the duration and severity of clinical signs were markedly reduced amongst vaccinated animals exposed to a severe live-virus challenge. Appropriate use of this vaccine should lead to a marked reduction in the frequency, severity and duration of outbreaks of equine influenza in North America.  相似文献   

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Laboratory trials were conducted to compare the efficiency of two vaccines against Marek's disease (MD) on the basis of the dynamics of post-vaccination viraemia and by means of a challenge test. Two groups of the HX-SL hybrid layers, each containing 40 birds, were vaccinated with the MARVAK cellular vaccine manufactured in Czechoslovakia (100 PFU per chick) or with the Insel Riems vaccine manufactured in the GDR (1000 PFU per chick). In weekly intervals, half the birds of each group were tested for post-vaccination viraemia and the other half, including 20 non-vaccinated birds, were infected by contact with the pathogenic virus of MD from the second day of age. The viraemia in the birds vaccinated with MARVAK culminated in the third week of age when it reached the average value of 25 PFU/10(7) leucocytes; later on, by the eighth week of age, it decreased to 0.62 PFU/10(7) leucocytes. The maximum number of viraemic chicks was found in the third and fourth week of age (80%); on an average it ranged from 60%. The average viraemia in the chickens treated with the vaccine from the GDR ranged from 1.6 to 3.6 PFU/10(7) leucocytes in the second to eighth week of age. A 100% positivity of the tested birds was found in the sixth week of age; it ranged around 70% on an average. In all the challenged groups of birds the precipitation antigen of Marek's disease was detected in feather follicles already 14 weeks from contact infection.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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The effect of a novel bovine mastitis trivalent vaccine, containing Staphylococcus aureus capsular polysaccharide type 5 (T5), 8 (T8), and 336 (T336), on lymphocyte subpopulations, antibody production, and neutrophil phagocytosis was evaluated. Twenty pregnant heifers were immunized with either the trivalent alone, trivalent emulsified in Freund's incomplete adjuvant (FICA), trivalent in aluminum hydroxide, or adjuvant only (FICA). Immunization was done 30 d before the expected calving date followed by 2 boosts in a 2-week interval. Compared to FICA, serum antigen-specific immunoglobulin (Ig)G1 and IgG2 were significantly increased in all the vaccinated groups before parturition and sustained until 3 wk postpartum. In comparison with the trivalent alone, formulation with either adjuvant enhanced production of IgG2, but not IgG1. Immune sera, which contained the highest amount of antibodies, slightly increased neutrophil phagocytosis to the 3 serotypes of killed S. aureus, but most of the differences were not significant due to large variation between the cows. The percentage of CD4+ lymphocyte was significantly higher in vaccinated groups than that of FICA 4 wk after the primary immunization. In comparison with FICA, cows inoculated with trivalent vaccine and adjuvants had an increased percentage of CD8+ lymphocytes at 2 time points, 2 wk before and after calving. Our results indicated that the whole cell trivalent vaccine, with or without adjuvants, is able to elicit antibody responses specific to the 3 capsular polysaccharide antigens. The increase of T8-specific IgG2 was more noticeable when the vaccine was emulsified with adjuvants.  相似文献   

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Nobivac Tricat, a lyophilised trivalent modified live attenuated vaccine is routinely used to protect cats against three commonly diagnosed feline viral pathogens namely herpesvirus, calicivirus and panleukopenia virus. The recognition of feline leukaemia virus (FeLV) as an important viral pathogen has prompted the development of an efficacious liquid recombinant subunit FeLV vaccine (p45 envelope protein). Lyophilised Tricat vaccine was dissolved in the liquid FeLV vaccine and no detectable deleterious effect on the titre of any of the live virus components was observed after 2h incubation. In vivo studies where the vaccines were mixed in the same syringe prior to inoculation showed no alteration to the safety profile assessed by repeat and overdose studies. Serological comparisons of the modified live viral antibody titres showed no evidence of reduced responses following administration of the mixed products. Challenge studies using pathogenic herpesvirus and FeLV revealed no difference in the degree of clinical protection. This paper shows that neither safety nor efficacy is adversely affected as a result of mixing the two vaccines.  相似文献   

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