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1.
Evaluation in swine of a subunit vaccine against pseudorabies   总被引：2，自引：0，他引：2  
A subunit vaccine against pseudorabies virus (PRV) was prepared by treating a mixture of pelleted virions and infected cells with the nonionic detergent Nonidet P-40 and emulsifying the extracted proteins incomplete Freund's adjuvant. Three 7-week-old pigs without antibodies against PRV were given 2 IM doses of this vaccine 3 weeks apart. Thirty days after the 2nd vaccination, 10(6) median tissue culture infective doses (TCID50) of a virulent strain of PRV were administered intranasally. Tonsillar and nasal swabs were collected daily between 2 and 10 days after challenge exposure. The pigs vaccinated with the subunit vaccine were not found to shed virulent PRV. Two groups of five 7-week-old pigs vaccinated with commercially available vaccines, either live-modified or inactivated virus, and subsequently exposed to 10(6) TCID50 of virulent PRV, shed virulent virus for up to 8 days. The subunit vaccine induced significantly higher virus-neutralizing antibody titers than either the live-modified or inactivated virus vaccine.  相似文献   

2.
SUMMARY Two-week-old chickens, free of detectable maternal antibody to Newcastle disease virus (NDV), or with low levels of maternal antibody, were vaccinated with the V4 strain of NDV. Haemagglutination inhibition (HI) antibodies were determined at intervals after vaccination. Two hundred chickens were vaccinated by exposure to an aerosol, a dose of 106 50% embryo infectious doses (EID50) being allowed per chicken. Forty unvaccinated chickens were placed in direct contact with vaccinated chickens. Most of the vaccinated chickens and the incontact chickens had developed HI antibodies of titre ≥ 8 within 2 weeks of vaccination. The HI antibodies in many chickens persisted for at least 8 weeks. Control chickens in a shed 15 metres from the shed containing the vaccinated chickens did not develop HI antibodies to NDV. NDV could be isolated from some vaccinated chickens for 15 days after vaccination. An aerosol dose of 105EID50 per chicken failed to induce a serological response in 2 groups of 40 chickens each. HI antibodies were produced in 1 of 2 groups, each of 40 chickens, vaccinated with 106EID50 and in both of 2 groups of 40 chickens each vaccinated with 107EID50. Duplicate groups of 40 chickens were vaccinated with 106EID50 of V4 virus per chicken administered either as an aerosol, a coarse spray or a droplet placed in the conjunctival sac. HI antibodies were produced in all the groups of chickens.  相似文献   

3.
鸡新城疫(ND) La Sota、传染性支气管炎(IB) H120和传染性法氏囊病(IBD) B87弱毒株适当稀释后等量混合,经10日龄SPF鸡胚同胚接种联合培养,收获含毒鸡胚液和胎儿混合制成ND、IB、IBD三联活疫苗。接种7~14日龄SPF雏鸡7 d产生抗体,14~21d达到高峰,免疫期70 d以上,与单苗同步免疫并攻击强毒,试验结果无显著性差异。以10个使用剂量免疫SPF雏鸡,无ND、IB、IBD临床症状和剖检病变,其安全性和效力检验均达到相应单苗的标准要求。  相似文献   

4.
SUMMARY An experimental vaccine containing the avirulent Australian V4 strain of Newcastle disease virus was used to vaccinate 3- or 6-week-old chickens by aerosol and drinking water application. The chickens lacked maternally derived antibody to Newcastle disease virus. When the vaccine virus was diluted in tap water more than 90% of the infectivity was destroyed immediately. The addition of 0.25% skim milk prevented this loss and there was no loss in distilled water. Rates of inactivation at 37°C were similar in tap water and distilled water and were unaffected by the addition of skim milk. Both methods of vaccination resulted in the production of haemagglutination-inhibition antibodies which persisted for at least 8 to 12 weeks. The antibody response to aerosol vaccination was significantly better than that following drinking water vaccination. No clinical disease was induced by exposure to vaccine virus. Serum neutralisation antibodies paralleled those detected by haemagglutination-inhibition in chicks vaccinated once by drinking water. After revaccination through the drinking water, haemagglutination-inhibition antibodies were boosted temporarily while neutralising antibodies were maintained at an enhanced level. From chickens vaccinated by aerosol, Newcastle disease virus was recovered for 10 days from lungs and for 7 days from tracheas and caecal tonsils. Peak viraemia was detected 2 and 3 days after vaccination while both neutralising and haemagglutination-inhibition antibodies became detectable 5 days after vaccination.  相似文献   

5.
Laboratory and field tests were conducted to evaluate the immunogenicity of a live-virus vaccine against infectious laryngotracheitis (ILT) of chickens that was prepared using tissue-culture-modified strain C7. Eighty-three percent or more of chickens vaccinated by the ocular (OC) or intranasal (IN) route with 10(4.75) TCID50 of the attenuated strain C7 at 50 days of age were protected against challenge with a virulent strain of ILT virus without showing any clinical signs for 4 weeks post-vaccination (PV). When vaccine was administered by aerosol, however, only 65% of vaccinated chickens were protected against challenge. Fifty-seven percent of chickens vaccinated at 70 days of age maintained immunity for 6 months PV. Immune response in younger chickens was inferior to that in older ones. In the field trials, clinical observation revealed no adverse reactions caused by the vaccination, and 60% or more of broilers and 80% or more of layers vaccinated by the OC route were protected against challenge at 4 weeks PV. These results confirmed the safety and efficacy of the vaccine.  相似文献   

6.
The safety and efficacy of the cell-associated (C-A) vaccine prepared by chicken embryo fibroblast (CEF) cells infected with the tissue-culture-modified strain of infectious laryngotracheitis (ILT) virus were studied in chickens. Over seventy percent of chickens inoculated with the C-A vaccine by the subcutaneous (S.C.) or intramuscular (I.M.) route at 1 day of age was protected against challenge with a virulent strain of ILT virus without any clinical signs. Chickens vaccinated with the C-A vaccine at 1 day of age acquired immunity within 6 days after vaccination, and the protection rate maintained more than 60% until 10 weeks post-vaccination. The C-A vaccine was invariably effective for chickens at various age. There was no evidence that the development of immunity was hindered by further vaccination with Newcastle disease and infectious bronchitis combined live vaccine. In addition, the C-A vaccine was safe when chickens were inoculated with 10 doses. In the field trials of the C-A vaccine, no adverse reaction was observed, and over 65% of vaccinated chickens was protected against the challenge of the virulent ILT virus at 8 weeks after vaccination.  相似文献   

7.
Ten common kestrels (Falco tinnunculus) were used for this falcon herpes vaccine experiment. Four kestrels were subcutaneously given 1 ml of an attenuated falcon herpesvirus that had originally been isolated from the liver of an American prairie falcon (Falco mexicanus). This virus was then passaged 100 times on chicken embryo fibroblast cells (CEF-cells). Another 4 kestrels were given subcutaneously an inactivated falcon herpesvirus vaccine derived from the same American field strain. This vaccine was concentrated, inactivated by heat and betapropiolactone and emulsified in complete Freund's adjuvans. Two further kestrels served as controls and were not vaccinated. Twenty-one days after vaccination, all 10 kestrels were challenged with passage 3 of the American falcon herpesvirus. The 2 control kestrels died 6 days after challenge and 3 of those given the inactivated herpes vaccine died 9 days after challenge, with typical lesions of herpesvirus inclusion body hepatitis. Before the vaccination experiment, all 10 kestrels were free of serum neutralising antibodies to the falcon herpesvirus. Twenty-one days after vaccination, all 4 kestrels vaccinated with the attenuated vaccine, and one vaccinated with the killed vaccine, had seroconverted, having shown no symptoms to the challenge with a low passage virulent American herpesvirus strain. Following the challenge their antibody titres to falcon herpesvirus increased. No herpesvirus was isolated from any of the cloacal swabs taken during this experiment, indicating that there is no danger for any other birds from the attenuated herpesvirus vaccine. This experiment clearly shows that an attenuated falcon herpesvirus vaccine can protect kestrels from fatal inclusion body hepatitis.  相似文献   

8.
The avirulent Newcastle disease virus strain designated NDV-6/10, selected by B. Lomniczi at the Veterinary Medical Research Institute, Hungarian Academy of Sciences, is completely safe for day-old chickens by aerosol vaccination. Aerosol immunization using the Hungarian-made MASTERDROP generator (particle size: maximum 7 microns) caused no vaccination reactions among 206,000 chickens with different maternal antibody levels. Other vaccines given simultaneously did not significantly affect the protection elicited against Newcastle disease (ND). Almost 100% and 90% of the aerosolized chickens survived subcutaneous challenge with 10(6) LD50 NDV at 30 and 50 days old, respectively. A single immunization is sufficient for broilers; however, parent flocks should be revaccinated at 7 so 8 weeks old.  相似文献   

9.
Ten pigs, aged 85 days, were vaccinated with a subunit vaccine containing 32 g of classical swine fever virus glycoprotein E2 (gp E2) (group 1), and a further 10 pigs were vaccinated with a C strain vaccine (104±0.15 TCID50/ml), produced by amplification in minipig kidney (MPK) cell culture (group 2). Nine non-vaccinated pigs served as a control group (group 3). Serum samples were collected before (day 0) and at 4, 10, 21 and 28 days after vaccination and were analysed by two commercially available enzyme immunoassays and by a neutralizing peroxidase-linked assay (NPLA). At the same times, peripheral blood was taken for determining the total leukocyte count and the body temperature was taken daily. Antibodies were not detected in serum samples collected before vaccination (day 0), and no side-effects that could be connected with vaccination were observed during the trial. Ten days after vaccination 6/10 pigs vaccinated with the subunit vaccine were seropositive. On days 21 and 28, the ratios of serologically positive to vaccinated pigs were 9/10 and 10/10, respectively. Four of the ten pigs that were vaccinated with the C strain vaccine were positive on day 21 and 9/10 on day 28. However, the results of the NPLA showed that only 4/10 pigs had an antibody titre >1:32 at the end of the trial in both the vaccinated groups, even though the subunit vaccine initiated an earlier and higher level of neutralizing antibodies than the vaccine produced from the C strain. Challenge was performed 28 days after vaccination on four randomly selected pigs from both vaccinated groups. The pigs survived the challenge without showing any clinical signs of classical swine fever (CSF), while two nonvaccinated control pigs died on the 10th and 12th days after infection.  相似文献   

10.
In this study, two highly pathogenic avian influenza (HPAI) H5N8 viruses were isolated from chicken and geese in 2018 and 2019 (Chicken/ME-2018 and Geese/Egypt/MG4/2019). The hemagglutinin and neuraminidase gene analyses revealed their close relatedness to the clade-2.3.4.4b H5N8 viruses isolated from Egypt and Eurasian countries. A monovalent inactivated oil-emulsion vaccine containing a reassortant virus with HA gene of the Chicken/ME-2018/H5N8 strain and a bivalent vaccine containing same reassortant virus plus a previously generated reassortant H5N1 strain (CK/Eg/RG-173CAL/17). The safety of both vaccines was evaluated in specific-pathogen-free (SPF) chickens. To evaluate the efficacy of the prepared vaccines, 2-week-old SPF chickens were vaccinated with 0.5 mL of a vaccine formula containing 108/EID50 /dose from each strain via the subcutaneous route. Vaccinated birds were challenged with either wild-type HPAI-H5N8 or H5N1 viruses separately at 3 weeks post-vaccine. Results revealed that both vaccines induced protective hemagglutination-inhibiting (HI) antibody titers as early as 2 weeks PV (≥5.0 log2). Vaccinated birds were protected clinically against both subtypes (100 % protection). HPAI-H5N1 virus shedding was significantly reduced in birds that were vaccinated with the bivalent vaccine; meanwhile, HPAI-H5N8 virus shedding was completely neutralized in both tracheal and cloacal swabs after 3 days post-infection in birds that had been vaccinated with either vaccine. In conclusion, the developed bivalent vaccine proved to be efficient in protecting chickens clinically and reduced virus shedding via the respiratory and digestive tracts. The applicability of the multivalent avian influenza vaccines further supported their value to facilitate vaccination programs in endemic countries.  相似文献   

11.
Two experiments were conducted to evaluate the virulence and vaccination efficacy of a Mycoplasma gallisepticum (MG) isolate designated MG Intervet 6/85. Virulence of the strain was determined by evaluation of airsacculitis scores following aerosol exposure to the isolate before and after 10 sequential passes in either commercial broiler chickens or commercial turkeys. Two-week-old specific-pathogen-free chickens were vaccinated by aerosol exposure. The birds were challenged with the R' strain of MG at either 4 or 8 weeks post-vaccination. Efficacy was evaluated by airsacculitis scores determined 21 days after challenge. Ten repetitive back-passes of the isolate in chickens and turkeys did not substantially increase the virulence. Virulence for both chickens and turkeys was minimal, while protection elicited by aerosol vaccination in young chickens against virulent R' strain was significant (P less than or equal to 0.05) compared with unvaccinated controls.  相似文献   

12.
重组禽流感灭活苗和禽流感灭活苗对鸡免疫效果的观察   总被引：3，自引：3，他引：0  
用重组禽流感灭活苗接种10日龄、14日龄和21日龄的SPF鸡,接种后HI抗体效价无显著差异。将H5N1和H5N2疫苗分别接种21日龄SPF鸡,结果表明,H5N1和H5N2均能刺激SPF鸡产生较高的HI抗体;分别接种三黄鸡,接种后21 d,H5N1能刺激三黄鸡产生较高的HI抗体;而H5N2不能刺激三黄鸡产生合格的HI抗体,与SPF鸡免疫组相比差异显著。经过二次接种,HI抗体平均为8.9 log2,与SPF鸡组接种后42 d的各组相比差异不显著,而与一免后21 d的各组HI抗体效价相比差异显著。表明应用禽流感灭活苗对三黄鸡免疫接种,必须进行二免方可达到理想免疫效果,而应用重组禽流感灭活苗对三黄鸡进行免疫接种,一次免疫即可获得较高的HI抗体效价。  相似文献   

13.
A vaccine containing crude Toxoplasma gondii rhoptry proteins incorporated in the immunostimulating complexes (ISCOM) adjuvant was tested in pigs for protecting against tissue cyst formation. For this, 38 mixed breed pigs were divided into four groups, G1 (vaccinated challenged, n=10) received two doses (100 microg/dose) of the rhoptry vaccine at days 0 and 21, G2 (vaccinated challenged, n=10) received viable tachyzoites (7 x 10(7)) of the RH strain at day 0, G3 (unvaccinated challenged, n=10) and G4 (unvaccinated unchallenged, n=8). Pigs were challenged with 4 x 10(4) VEG strain oocysts 57 days later. The G1 pigs produced high IgG antibody levels in the indirect enzyme-linked immunosorbent assay (ELISA) after the second dose of rhoptry vaccine, but were not clinically protected against a high dose oocyst challenge. Partial protection was observed in G1 at the chronic phase of infection, when compared with G3. Pigs in group 2 developed high antibody levels and were protected against clinic signs. T. gondii was not detected in two (G1) and three (G2) pigs by mouse bioassay. The results indicate partial protection in pigs vaccinated with a rhoptry vaccine.  相似文献   

14.
用鸡新城疫-传染性法氏囊病二联灭活疫苗(La Sota+HQ株)分别免疫1、7、14日龄SPF雏鸡,1日龄免疫组于25日龄采血,法氏囊病中和抗体几何平均值为15.5log2,攻毒保护10/10;7日龄免疫组于30日龄采血,法氏囊病中和抗体几何平均值为14.8log2,攻毒保护10/10;14日龄免疫组于35日龄采血,法氏囊病中和抗体几何平均值为15.4log2,攻毒保护10/10。3组在50日龄时法氏囊病中和抗体几何平均值依次为16log2、16.1log2、15.9log2,攻毒保护均为10/10。用鸡新城疫-传染性法氏囊病二联灭活疫苗(La Sota+HQ株)免疫带有母源抗体的1、7、14日龄商品肉鸡,免后25 d血清法氏囊病中和抗体几何平均值分别为12.4log2、15log2、14.2log2,攻毒保护分别为8/10、10/10、9/10;3组在50日龄时法氏囊病中和抗体几何平均值依次为16.2log2、15.7log2、15.5log2,攻毒保护均为10/10。  相似文献   

15.
A fully attenuated apathogenic reovirus vaccine was developed by 235 serial passages of S1133 strain avian reovirus in embryonating chicken eggs and 100 additional passages in chicken embryo fibroblast (CEF) cultures, 65 of which were cultured at 32 C. Chickens with and without maternal antibodies to avian reovirus were vaccinated subcutaneously at 1 day of age and challenged via footpad at 14 days of age. It appeared that the 40th, 66th, and 100th CEF passage levels were apathogenic at doses ranging from 10(2.5) to 10(6.8) TCID50/chick. No gross or microscopic lesions of tenosynovitis developed in vaccinated chicks. Vaccinated chicks were protected against challenge; unvaccinated control chickens were not.  相似文献   

16.
Growing turkeys were partly protected against fowl cholera 4 days after vaccination with the live Clemson University (CU) strain of Pasteurella multocida administered in drinking water, and they were highly protected from 1 to 4 weeks after vaccination. The commercially available lyophilized vaccine and the freshly cultured vaccine of the CU strain did not differ in the level of immunity induced. Immunity was relatively high in turkeys vaccinated with 1:2 and 1:4 dilutions of the recommended dosage (4 X 10(8) P. multocida) but was significantly (P less than 0.05) lower in turkeys vaccinated with a 1:8 dilution of the recommended dosage. Immunity continued for 13 weeks after the last vaccination in turkeys vaccinated twice 3 weeks apart, but it persisted for only 8 weeks in those vaccinated only once.  相似文献   

17.
Studies were undertaken to determine the influence of repeated revaccination on the immune response in immuno-competent turkeys as measured by humoral antibody and resistance to challenge. Protection was better in turkeys given the LaSota spray vaccine at 4 weeks and 30 days later than in turkeys given one vaccination by spray or intramuscular route or exposed 4 times at 10-day intervals by the aerosol route. The anamnestic response, as measured by the HI tests to revaccination with the same immunogen, was not evident by the 3rd day postrevaccination but was observed on the 7th day. The interval between primary and secondary vaccination was found to be important to a true and optimal anamnestic response. Response was greater, however, in vaccinated turkeys exposed to VVND, a more virulent virus antigenically different from the vaccine strain. Exposure to LaSota vaccine by the intramuscular route gave a poorer HI response than LaSota given by aerosol.  相似文献   

18.
The immunogenicity and safety of an attenuated Bordetella bronchiseptica vaccine for swine atrophic rhinitis (AR) was evaluated in 22 hysterectomy-produced, colostrum-deprived pigs and 18 conventional pigs. None of 8 pigs inoculated at 7 days of age intranasally with greater than or equal to 3 X 10(5) colony-forming units (CFU) of vaccinal strain/pig and 2 of 5 pigs inoculated at 7 days of age intranasally with 3 X 10(4) CFU of the vaccinal strain/pig developed AR after intranasal challenge exposure with a virulent strain at postinoculation week (PIW) 3. The remaining 3 vaccinated pigs and 4 nonvaccinated pigs developed AR. Thirteen pigs were inoculated intranasally with 3 X 10(6) to 3 X 10(9) CFU of the vaccinal strain at 7 days of age. At PIW 12, the pigs were killed and necropsied. None of the pigs had clinical signs of AR and/or pneumonia. Virulence was studied by transmission of vaccinal strain through 3 serial growing passages on the nasal mucosa of a litter of hysterectomy-produced colostrum-deprived pigs. Inoculum (nasal swab samples from 2 pigs 4 days after inoculation with 10(8) CFU of vaccinal strain at 5 days of age) was inoculated into the nasal cavity of 2 nonvaccinated pigs. This procedure was repeated 3 times. After the 1st passage, the vaccinal strain was recovered on postinoculation day 4, but after postinoculation day 4, the vaccinal strain was not recovered until the end of the 3rd passage. Turbinate atrophy or pneumonia was not recognized in these inoculated pigs. The vaccinal strain provided immunogenicity without ill effects.  相似文献   

19.
The consequence of cryptosporidiosis on the immune response of vaccinated chickens against Newcastle disease and/or avian influenza was studied by using 240, 1 day old, male, white Hy-Line chicks and divided into 8 groups and subgroups. Each group or subgroup was consisting of 30 chicks (15?×?2 replicates). The first and second groups were kept as unvaccinated control, G1uninfected and G2 infected. G3, G4 and G5 contained 2 subgroups A&B (G3A, G3B, G4A, G4B, G5A and G5B). Chicks of subgroup A were vaccinated only while chicks of subgroup B were infected and vaccinated. These chicks were orally inoculated with 5?×?105 oocysts of Cryptosporidium baileyi (C. baileyi) at 2 days of age. Chickens were vaccinated intraocular with live Newcastle disease (ND) vaccine (Hitchner on day 7th and LaSota on day 17th of chicken life) (G3) or vaccinated by subcutaneous route with Volvac®- H5N2- AI vaccine on day 10 of chicken life (G4). Last group (G5) was infected similarly and vaccinated with ND and AI vaccines with the same day, dose and route of vaccination for each one. Random blood samples were collected for 3 weeks post-vaccination for investigation of humoral immune response against Newcastle and/or avian influenza vaccines by the haemagglutination inhibition (HI) test. The results showed that H5N2 vaccine at day 10 of chicken life is effective in chickens indicated by the geometric mean of HI titer against AI virus. The findings of this study showed that the infection with Cryptosporidia in the broiler chicken has a depressive effect on the immune status of the birds vaccinated against ND and/or AI vaccination. Moreover, the obtained protection rates against challenge with virulent ND virus observed to be parallel to the results of HI- test. Also, by using 2 different antigens (one commercial and field prepared antigen) to avian influenza virus, lower Geometric mean (GM) HI titer were appeared in infected and vaccinated group than vaccinated group only. A study of the relative lymphoid organs weight such as bursa of Fabricius from the experimental chicks indicated that those organs were comparable between the groups infected-vaccinated and vaccinated only. Non significant variations in final live weight between uninfected control and infected groups were indicated. Also, H5N2-AI vaccination at 10 days old did not affect the final live weight. ND and/or AI Vaccination could not be a substitute to application of good hygienic measures and fecal examination of the birds especially for protozoal diseases such as cryptosporidiosis. It could be concluded that cryptosporidiosis could be one cause of ND and/or AI vaccination failure in poultry farms.  相似文献   

20.
A canine parainfluenza viral vaccine was developed and shown to be safe by absence of clinical disease in vaccinated dogs and by inability to isolate vaccine virus from blood or nasopharyngeal swabs. Backpassage in susceptible dogs, using blood of vaccinated dogs, could not be demonstrated. The vaccine produced neutralizing antibody when administered either intramuscularly or subcutaneously; however, a significantly higher immune response was obtained by intramuscular inoculation. Differences in the antibody response were not produced by tenfold dilutions of vaccine virus ranging from 10(2.9) to 10(5.9) median tissue culture infective doses. The presence of neutralizing antibody was associated significantly with decreased respiratory shedding period of challenge virus by vaccinated dogs compared to seronegative control dogs. Six days after aerosol exposure to virulent challenge virus, 100% of the controls (n = 5) but only 15% of the vaccinated dogs (n = 3) shed virus. Seven days after challenge exposure, virus could not be recovered from the vaccinated dogs, but 80% of the control dogs shed virus. An anamnestic response occurred in vaccinated dogs but not in the seronegative control dogs following challenge exposure. A mild clinical disease was produced in 3 of the 5 seronegative control dogs but not in the 20 vaccinated dogs.  相似文献   

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