Q fever (Coxiella burnetii) investigations in dairy cattle: persistence of antibodies after vaccination.

The immune response and persistence of antibodies were investigated in dairy cattle vaccinated with formalin-inactivated phase (ph) I Coxiella burnetii vaccine agglutinating antibody geometric mean titer (GMT) of 193.2 at 1 month after vaccination compared to a GMT of 2.0 for nonvaccinated calves. The agglutinating antibodies gradually decreased in vaccinated cattle, but the GMT remained approximately 4 times higher than that for the nonvaccinated group for at least 20 months. Results of serotests at 2 months after revaccination indicated a rapid increase in the GMT to 177.0 with agglutinating titers between 1:64 and 1:512.     

Efficacy of a vaccine to prevent Chlamydia- or Campylobacter-induced abortions in ewes

In a sheep flock, Chlamydia psittaci, Campylobacter fetus, Ca jejuni, and Salmonella dublin caused abortions. A vaccine that contained C psittaci type I from 2 sources: a cow with pneumonia and an aborted ovine fetus, Ca fetus, Ca jejuni, and 4 strains of K99 Escherichia coli was given to 240 ewes before they were bred. All fetuses, placentas, and lambs, that died within 36 hours of birth were examined for infectious agents. Of 55 abortions, 30 (55%) were caused by Chlamydia or Campylobacter spp; 25 of the 30 (83%) abortions took place in the nonvaccinated group (n = 240). Forty-five more lambs survived in the vaccinated group than in the nonvaccinated group. Abortion rates for Chlamydia and Campylobacter spp (2.1 vs 10.4% in vaccinated and nonvaccinated groups, respectively) were significantly different (P = 0.003). Abortion rates for S dublin were not significantly different between groups. The Salmonella epizootic was controlled quickly by sanitation and treatment procedures. The vaccine was at least 80% efficacious against Chlamydia and Campylobacter spp and appeared to be protective.     

Protection from parainfluenza-3 virus and persistence of infectious bovine rhinotracheitis virus in sheep vaccinated with a modified live IBR-PI-3 vaccine.

Ewes (N = 7) and their lambs (N = 12) were vaccinated with a commercial modified live infectious bovine rhinotracheitis-parainfluenza type 3 virus vaccine. Both the vaccinated ewes and lambs and a group of unvaccinated ewes (N = 8) and their lambs (N = 13) were subsequently challenged with virulent parainfluenza type 3 virus. Although absolute immunity to infection and clinical response was not conferred, the clinical response was less severe in vaccinated lambs. Vaccinated animals also shed parainfluenza type 3 virus in nasal secretions for a shorter time than nonvaccinated animals. Some vaccinated lambs developed a persistent infectious bovine rhinotracheitis virus infection that was recrudesced by treatment with dexamethasone. It was concluded that vaccination was of benefit in reducing the severity of infection with parainfluenza type 3 virus. However, the inclusion of infectious bovine rhinotracheitis virus in a vaccine for sheep respiratory tract disease is highly questionable as it might increase the risk factor associated with vaccination. The consequences of the persistence of infectious bovine rhinotracheitis virus are now known.     

The incidence of caseous lymphadenitis in Alberta sheep and assessment of impact by vaccination with commercial and experimental vaccines.

In Alberta, caseous lymphadenitis (CLA) is one of the leading causes of lamb and mutton carcass condemnation. In this study, serologic results confirmed a high (50-94%) incidence of exposure to Corynebacterium pseudotuberculosis, the causative agent of CLA, in mature, unvaccinated sheep in southern Alberta. To assess the efficacy and impact of vaccination with 2 commercial (Glanvac-6 and Case-Vac) and 1 experimental (WC+ MDP-GDP) CLA vaccines, a series of 3 field trials in 3249 ewes and lambs was conducted in affected flocks from 1992-1996. Efficacy was assessed from the serological response to vaccination, prevalence and size of injection site reactions by treatment, and the incidence of CLA abscesses. Overall, agglutinating antibody titres to C. pseudotuberculosis in lambs vaccinated with WC+MDP-GDP and Case-Vac remained significantly elevated above nonvaccinated control lambs for the 12 mo period after the initial vaccination. Lambs vaccinated with the WC/MDP-GDP maintained higher titres (P < 0.06) than those vaccinated with Case-Vac for the period from 6 to 12 mo after vaccination. Agglutinating antibody titres for lambs vaccinated with Glanvac did not differ from those of controls at any point during the 12 mo period after vaccination. The number of injection site reactions was elevated in lambs vaccinated with Glanvac as compared to those vaccinated with WC+MDP-GDP but the size of injection site reactions did not significantly differ. Sheep vaccinated with WC+ MDP-GDP also had a reduced incidence of putative CLA abscesses, although confirmation of the presence of C. pseudotuberculosis was only successful in a small number of instances.     

Protection of lambs against enteric colibacillosis by vaccination of ewes

Pregnant ewes were vaccinated twice, seven weeks and three weeks before lambing, with a multivalent formalin-killed Escherichia coli vaccine containing an added K99, F41 antigen preparation. Lambs born to vaccinated and unvaccinated ewes were exposed to oral infection with E coli B44 (09:K30, K99, F41). All 10 lambs from vaccinated ewes were protected whereas all 10 control lambs developed severe diarrhoea and five died or were killed in extremis. In the following year, previously immunised ewes were given a single dose of the vaccine two weeks before lambing. Eleven of their 12 lambs were protected against a similar challenge, which caused the death of six of eight control lambs and severe diarrhoea in the two survivors. Higher levels of antibody to the K99, F41 preparation were detected by enzyme-linked immunosorbent assay in the serum and colostrum from vaccinated ewes and in the serum of their lambs when compared with similar samples from control ewes and lambs.     

Colostral transfer of Bacteroides nodosus antibodies in sheep.

Ovine contagious foot rot may cause lameness in sheep, resulting in decreased wool growth and low weight gain. Affected neonatal lambs are difficult to treat, and treatment is labor intensive; thus, a method of prevention is warranted. Vaccination of ewes with a multivalent vaccine in an oil adjuvant induced development of antibody to the somatic O antigen of Bacteroides nodosus, and this antibody was detected in serum of newborn lambs after consumption of colostrum from the vaccinated ewes. Antibody titers were determined in 48 unvaccinated ewe/lamb pairs, and in 50 once-vaccinated and 78 twice-vaccinated pairs. Serum and colostrum O-agglutinin titers to B nodosus were determined by a microtitration agglutination test. Lambs from vaccinated ewes had significantly (P less than 0.05) higher O-agglutinin titers than those from unvaccinated ewes, and double vaccination of ewes resulted in the highest potentially protective titers (greater than 1:2,400) in ewes and lambs.     

A field trial to assess the therapeutic and prophylactic effect of a foot rot vaccine in sheep

An 18-week field trial was conducted on a sheep ranch to evaluate the therapeutic and prophylactic effect of a commercial foot rot vaccine. Two hundred sheep were included in the study, 100 with detectable foot rot lesions and 100 without. Approximately 50 sheep from each group were selected randomly and vaccinated twice against foot rot at a 6-week interval in the late spring 1984; the remaining sheep acted as nonvaccinated controls. Therapeutic effect of the vaccine was demonstrated by a cure rate of 53% in vaccinated, foot rot-affected sheep vs a cure rate of 19% in nonvaccinated, foot rot-affected sheep. Prophylactic effect of the vaccine was demonstrated by a foot rot prevalence at the end of the 18-week period of 9% for vaccinated sheep vs 53% for nonvaccinated sheep. Associations of foot rot lesions and vaccination with body condition were found to be significant, as was the association between foot rot lesions and mortality.     

Effects of an orally administered live Escherichia coli pilus vaccine on duration of lacteal immunity to enterotoxigenic Escherichia coli in swine

Primigravid swine were vaccinated orally with a live enterotoxigenic Escherichia coli (ETEC) strain that produces pilus antigen K99. The titers of K99 antibody in colostrum and milk of vaccinates remained higher than those of nonvaccinated controls through the first lactation after vaccination (4 weeks). Some control swine had low titers of K99 antibody in colostrum or developed low titers of K99 antibody in milk during lactation. Lacteal K99 antibody titers of vaccinates dropped to control levels during the second lactation, 6 months after vaccination. Pigs suckling vaccinates and controls were equally susceptible to challenge exposure to K99+ ETEC during the second lactation. Orally vaccinated swine given a parenteral booster vaccination (with killed K99+ ETEC) during their second gestation had K99 antibody in milk through their second lactation. During the second lactation, these orally vaccinated parenterally revaccinated swine had higher titers of K99 antibody in postcolostral milk than did nonvaccinated controls, controls given only the parenteral booster injection, or controls vaccinated parenterally during both gestations.     

Amniotic and allantoic fluids from experimentally infected sheep contain immunoglobulin specific for Chlamydophila abortus

Chlamydophila abortus, the aetiological agent of enzootic abortion of ewes (EAE), replicates in trophoblast cells leading to their destruction and dissemination of the bacterium to foetal organs. To further understand the pathogenesis of EAE, amniotic and allantoic fluids were collected from experimentally infected pregnant ewes at 30 (7 samples from each fluid), 35 (8 samples from each fluid), 40 (10 samples from each fluid) and 43 (6 amniotic fluids and 7 allantoic fluids) days post-infection to determine pathogen numbers and other markers of infection. Whilst experimentally infected ewes had characteristic placental lesions, only two amniotic and seven allantoic fluid samples were positive for C. abortus by real-time PCR. In contrast, all amniotic and allantoic fluids were positive for immunoglobulin. Immunoglobulins were generally detected earlier in allantoic fluid than in amniotic fluid and the numbers of samples containing immunoglobulins increased as infection progressed. IgG in amniotic and allantoic fluids was shown to be specific for C. abortus, and reacted with the major outer membrane proteins, polymorphic outer membrane protein and macrophage infectivity potentiator protein. A comparison of two-dimensional immunoblots using purified IgG from the allantoic fluid, amniotic fluid, ewe serum and foetal serum of a C. abortus infected animal at 40 days post infection indicated a pattern of reactivity intermediate between that of the ewe serum and the foetal serum. Results suggest that a maternal source of immunoglobulin is predominant at 30 days post-infection but that foetal derived antibodies may be contributed at a later stage.     

Necrotic oophoritis in heifers vaccinated intravenously with infectious bovine rhinotracheitis virus vaccine during estrus

Twenty-two Hereford heifers were injected IM with prostaglandin F2 alpha a, 11 days apart to synchronize estrous cycles. Twelve of 14 heifers that had signs of estrus were inoculated IV with 1 of 3 modified-live infectious bovine rhinotracheitis virus vaccines, and 2 were assigned to a nonvaccinated control group. Also, 6 of the 8 anestrous heifers were inoculated IV with 1 of the 3 vaccines on the fourth day after the last prostaglandin injection and the other 2 were assigned to the nonvaccinated group. Vaccine virus was isolated from the blood and nasal and vaginal secretions from the vaccinated heifers on postvaccination days 4, 7, and 9. On postvaccination day 9, all heifers were ovariectomized and ovarian tissues were processed for virus isolation and histologic examination. Vaccine virus was isolation and histologic examination. Vaccine virus was isolated from ovarian tissues of some heifers in each of the vaccine groups. Necrotic oophoritis characterized by multifocal areas of ovarian tissue necrosis, hemorrhage, and mononuclear lymphocytic infiltration was observed. The corpora lutea and surrounding ovarian tissues taken from vaccinated heifers in each group had varying amounts of necrotic and inflammatory change, but the changes appeared to be more severe in 1 group than in the other 2. Virus also was isolated from 2 of the controls; these heifers apparently became infected with vaccine virus that had been excreted from the vaccinated animals.     

Bovine antibody against Streptococcus agalactiae, type Ia, produced by preparturient intramammary and systemic vaccination.

Four pregnant heifers were immunized by the intramammary route with killed or live Streptococcus agalactiae vaccine, and a 5th heifer was vaccinated by the intramuscular route with killed vaccine. Antibody in the colostrum from vaccinated and non-vaccinated glands was compared. Antibacterial glands was compared. Antibacterial antibody titers of the 4 immunoglobulin classes were determined by indirect fluorescent antibody assay. Although the content of immunoglobulin G1 (IgG1), IgG2, and IgM in the colostrum from the vaccinated glands was not substantially different from the nonvaccinated glands, IgA content was considerably greater in the former. Antibody specific to S agalactiae was isolated from all colostrum samples. The mouse passive protection test and Ouchterlony analysis were used to demonstrate the presence of type-specific antibody to Ia strain used for vaccination. The passive mouse protection test also was useful to compare the protective capacity of specific S agalactiae, type Ia, antibodies of immunoglobulin classes IgG, IgM, and IgA. Increased protective capacity of IgM and IgA over IgG1, on a weight basis, was demonstrated. The present study indicates that S agalactiae preparations, when introduced into the mammary gland, can give rise to local antibody synthesis in the vaccinated glands.     

The effects of vaccination of Merino ewes with an attenuated Australian bluetongue virus serotype 23 at different stages of gestation

SUMMARY A cell culture attenuated Australian bluetongue virus serotype 23 (BLU23) prototype vaccine was assessed for its effects on pregnant Merino sheep. Seventy-six ewes were vaccinated at 5 different stages of gestation, and the failure to lamb at term was as follows: 35 to 43 days of gestation, 20/36 (56%); 57 to 64 days of gestation, 3/10 (30%); 81 to 88 days of gestation, 3/10 (30%); 109 to 116 days of gestation, 0/10 (0%); 130 to 137 days of gestation, 0/10 (0%). Of 30 ewes vaccinated with a cell culture supernatant fluid control between 35 and 43 days of gestation, 6.7% (2/30) failed to lamb at term. Two ewes vaccinated with BLU23 vaccine between 35 and 43 days of gestation had lambs with hydranencephaly. All other lambs born were clinically normal. Three ewes vaccinated with BLU23 aborted. Two of these were vaccinated between 35 and 43 days of gestation, the 3rd between 81 and 88 days of gestation. Five lambs were born with BLU group antibody. Four of these were from ewes vaccinated between 35 and 43 days of gestation, and 2 of these had hydranencephaly. The fifth was from a ewe vaccinated between 57 and 64 days of gestation. The vaccine did not produce disease in adult sheep, but was a potent cause of early foetal death and to a much lesser extent foetal malformation.     

Use of long-term vaccination with a killed vaccine to prevent fecal shedding of Mycobacterium avium subsp paratuberculosis in dairy herds

OBJECTIVES: To determine whether vaccination with a killed vaccine prevents fecal shedding of Mycobacterium avium subsp paratuberculosis, to compare effectiveness of a culture and cull program in vaccinated and nonvaccinated herds, and to compare paratuberculosis-related preventive management in vaccinated and nonvaccinated herds. SAMPLE POPULATION: 58 commercial Dutch dairy herds. DESIGN: Cross-sectional study (study A) in vaccinated (n = 25) and nonvaccinated (29) herds of dairy cows. Longitudinal study (study B) in vaccinated (n = 2) and nonvaccinated (2) herds of dairy cows. PROCEDURE: In study A, fecal samples were obtained from adult cows in herds with and without a history of vaccination with a killed vaccine. Management measures were evaluated. In study B, fecal samples were obtained 4 times at 6-month intervals from cows older than 6 months. Cows that had positive test results were removed from the herd directly after the outcome of the culture. RESULTS: In study A, differences were not detected among the 25 herds that were vaccinated; culture results were positive for M avium subsp paratuberculosis in 4.4% of herds. In 29 herds that had not been vaccinated, culture results were positive in 6.7%. In study B, the percentage of positive results on culture decreased from 10.9% and 5.7% to 3.5% and 0%, respectively in the 2 vaccinated herds. In the 2 nonvaccinated herds, percentages decreased from 6.1% and 16.5% to 0% and 2.3%, respectively. Management practices were different between herds that were vaccinated and herds that were not; owners of herds that were not vaccinated followed more preventive management procedures and practiced less feeding of raw milk to calves. CONCLUSIONS AND CLINICAL RELEVANCE: Vaccination of calves with a killed vaccine does not prevent transmission of M avium subsp paratuberculosis; therefore, hygienic practices remain essential in herd management.     

Effects and use of a modified live Anaplasma marginale vaccine in beef heifers in California

Eighty-one 11-month-old, nonpregnant, Anaplasma marginale-seronegative beef heifers were allotted to 2 groups for evaluation of a modified live A marginale vaccine (n = 50 for vaccinated group and n = 31 for nonvaccinated group). The vaccine induced a mild form of anaplasmosis, as evidenced by a significant (P less than 0.01) decrease in the packed cell volume (PCV) between days 31 and 46 after vaccination. The lowest PCV was 11%, and 3 heifers had a PCV less than 20%. Slight lethargy was evident in some of the vaccinated heifers between days 30 and 45 after vaccination. All vaccinated heifers became seropositive to A marginale, as measured by the complement fixation test and the card test on days 35 and 42 after vaccination, respectively. All nonvaccinated heifers remained seronegative.     

嵌合型猪圆环病毒（PCV1—2）及PCV2 ORF2真核表达质粒对商品猪的免疫保护

应用本实验室构建的嵌合型猪圆环病毒（PCV1—2）及真核表达质粒pcDNA3．1／V5-His-ORF2作为免疫原免疫母源抗体ELISA效价在0．07～0．60不等的商品猪,9头猪随机分为4组,1组（3头）肌肉注射免疫10^3.5 TCID50的PCV1-2／头,2组（2头）肌肉注射真核表达质粒200μg／头,3组（2头）肌肉注射空载体（pcDNA3．1）200μg／头,4组（2头）不免疫作为攻毒对照组。于免疫后42d,PCV1—2组及真核表达质粒组产生了PCV2抗体。免疫后42d所有组攻毒PCV2和PRRSV,剂量分别为2×10^4.5 TCID50／头和10^6 TCID50／头。攻毒后21d,攻毒对照组猪淋巴结比免疫组显著肿大,免疫组猪血清、淋巴结中PCV2病毒栽量低于对照组,攻毒对照组猪淋巴结中PCV2抗原含量高于免疫组。这些结果表明,嵌合型PCV1-2及真核表达质粒肌肉注射免疫商品猪后,对PCV2感染能产生保护性免疫应答,有可能成为候选疫苗。     

Protection of the nursing pig against experimentally induced enteric colibacillosis by vaccination of dam with fimbrial antigens of E coli (K88, K99 and 987P)

Pregnant gilts were vaccinated with two doses of alhydrogel adsorbed fimbrial antigens of Escherichia coli (K88ab, K88ac, K99 and 987P) supplemented with beta toxoid of Clostridium perfringens type C. Their piglets, and piglets of nonvaccinated gilts, were subsequently orogastrically challenged with one or other of the four fimbrial types of enteropathogenic E coli. Some of the vaccinated animals were reinjected with a single dose of the vaccine during second gestation and their piglets, and piglets of non-vaccinated sows, were challenged the same way as were litters of gilts. Blood serum and colostra were examined for antibodies to the four fimbrial antigens of E coli and for antitoxin to beta toxin of C perfringens type C. It was found that: (1) a highly significant reduction in mortality and morbidity was achieved in vaccinated litters against all four challenge strains of E coli; (2) excretion of K88ab and K88ac but not of K99 and 987P challenge strains was significantly reduced; (3) revaccination of sows by a single dose of the vaccine during second gestation conferred complete protection against mortality and highly significant protection against morbidity; (4) no correlation was noted between colostral or seroagglutinins to fimbrial antigens of E coli and mortality rates in litters challenged with homologous fimbrial types of E coli, but good correlation was found between colostral precipitins to K88 antigens and mortality rates in litters; (5) antitoxin value in 97 per cent of colostrum of vaccinated sows was 10 iu equivalent of C perfringens type C toxin or more per ml of colostrum.     

Study of the reactivity and immunogenicity of a combined vaccine against abortion due to coxiellosis and chlamydiosis in sheep

Reactogenicity was studied in a combined vaccine against Q-fever and chlamydia-induced abortion in ewes; the vaccine consisted of a mixture of purified corpuscles of Chlamydia psittaci (100 micrograms) and Coxiella burnetii (50 micrograms). The immunogenicity of the combined vaccine, evaluated by the number of positive serums after vaccination and by the average geometric titre of antibodies, was the same as that of the vaccine separate constituents as to the antibodies to C. burnetii, but somewhat higher in the case of antibodies to Chlamydia psittaci. When studied on a smaller number of ewes, the combined vaccine had an optimum immunogenicity in the cases of the prevalence of Chlamydia psittaci over C. burnetii in the vaccine.     

Bordetella rhinitis in pigs: serum and nasal antibody response to Bordetella bacterins.

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.     

Strain predominance following exposure of vaccinated and naive pregnant gilts to multiple strains of porcine reproductive and respiratory syndrome virus

Two studies were performed in order to test the relative ability of different strains of porcine reproductive and respiratory syndrome virus (PRRSV) to replicate and cross the placental barrier in pregnant gilts. Study 1 comprised 6 nonvaccinated gilts. Study 2 comprised 8 nonvaccinated gilts and 12 gilts that were vaccinated twice before conception. On, or about, gestation day 90 all gilts were simultaneously exposed to 20 field strains of PRRSV (all strains were distinguishable by restriction fragment length polymorphism (RFLP) patterns). Gilts of study 1 were euthanized on day 7 postpartum. Gilts of study 2 were euthanized on, or about, gestation day 111. All gilts, pigs, and fetuses were tested for the presence and type of strain of PRRSV. Of 128 samples shown to contain PRRSV, 118 contained a single strain, 4 contained 2 strains, and 2 contained a strain or strains for which the RFLP pattern was undecipherable. Only 8 of the 20 strains were isolated from nonvaccinated gilts and their litters. And only 2 of the 20 strains (notably 2 of the same strains isolated from nonvaccinated gilts and their litters), were isolated from vaccinated gilts and their litters. Moreover, 1 of the 2 strains accounted for most (31 of 37; 84%) of the isolates from the vaccinated group. Collectively these results indicate that strains differ in their ability to replicate in pregnant gilts and cross the placental barrier. And they suggest that maternal immunity, although sometimes insufficient to prevent transplacental infection, can exert additional selective pressure.     

Hydrops amnii in sheep associated with hydranencephaly and arthrogryposis with wesselsbron disease and rift valley fever viruses as aetiological agents.

During the 1974/75 lambing season numerous reports were received from various parts of the Republic of South Africa and South West Africa of severe abdominal distension in ewes after vaccination with the attenuated Rift Valley fever and/or attenuated Wesselsbron disease vaccine. The ewes were vaccinated at different stages of gestation in spite of recommendations to the contrary, the syndrome being especially obvious in ewes immunized with one or both of these vaccines during the first trimester of pregnancy. In some of the flocks hydrops amnii was recorded in as many as 15% of the ewes. Many of the ewes so affected showed a prolonged gestation of up to 6-7 months and, towards the end of gestation, were unable to rise or walk. They eventually died of ketosis, hypostatic pneumonia and complications due to dystocia. The foetuses examined were malformed and larger than normal with a mass of 3,6-6,7 kg. They usually showed arthrogryposis, brachygnathy inferior, hydranencephaly, hypoplasia or segmental aplasia of the spinal cord and neurogenic muscular atrophy. The amnion contained 8,0-18,0 1 of amniotic fluid, the endometrium was oedematous, and cystic tube-like dilatations, 1-10 mm in diameter, filled with a clear fluid, were scattered in the endometrium. No definite conclusions as to the aetiology of the syndrome could be drawn from serological tests performed on the ewes, lambs or foetuses. Preliminary experimental work confirmed previous observations that the attenuated Wesselsbron disease vaccine virus is responsible for this syndrome and that the wild-type virus is also implicated. In addition, the attenuated Rift Valley fever vaccine virus was found to the responsible for arthrogryposis and hydranencephaly without hydrops amnii and for micrencephaly and arthrogryposis associated with hydrops amnii in the ewe.