Allergy in cattle after foot-and-mouth disease vaccination.

BHK cell derivatives, saponin and aluminium hydroxide, all of which are commonly present in foot-and-mouth disease vaccines, were injected subcutaneously into 10 cattle and the serum levels of anti-BHK reagins and passive haemagglutinating antibodies were followed. The reaginic antibodies rose to a peak titre one to two weeks after the stimuli and waned during the third week. They had a serum half life of about three days, assuming exponential decay, and were generally undetectable four weeks after last contact with antigen. Passive haemagglutinins were slower to develop and two or more stimuli were usually required to produce detectable antibody levels. They were also slower to subside and were demonstrable for at least 10 weeks after last contact with antigen in most cases. Clinical reactions provoked by the intradermal injection of lysate into sensitised cattle were not correlated with the serum reagin or passive haemagglutinin levels or their ratio to one another at time of the reactions. The reasons for this are discussed.     

Simultaneous vaccination of cattle against foot-and-mouth disease and rinderpest

Summary A total of 118 local cattle in the Sultanate of Oman were divided into three groups, one which received a trivalent inactivated foot-and-mouth disease vaccine, another which received attenuated tissue culture rinderpest vaccine and a third which received both vaccines simultaneously at separate sites on opposite sides of the neck. The serological response to vaccination was monitored at day 0,21 and 42 in virus neutralisation tests. The simultaneous administration of the two vaccines produced no ill effects and the serological responses did not differ significantly from the response to either vaccine given separately.

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Resumen Un total de 118 bovinos en Oman se dividieron en tres grupos, recibiendo el primero una vacuna trivalente inactivada de aftosa, el segundo recibió una vacuna preparada en cultivos celulares y atenuada, recibiendo el tercer grupo ambas vacunas simultáneamente en el lado derecho e izquierdo de la tabla del cuello. La respuesta serológica a la vacunación se estudió los días 0,21 y 42 mediante la técnica de neutralización viral. La administración simultánea de las dos vacunas antes mencionadas, no produje efectos indeseables y la respuesta serológica no difirió significativamente de aquella obtenida mediante la aplicación de ambas vacunas en forma separada.

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Résumé 118 bovins d’origine locale du Sultanat d’Oman ont été divisés en trois groupes: l’un a re?u un vaccin anti-aphteux trivalent, un autre le vaccin antibovipestique atténué sur cultures de tissu, le troisième les deux vaccins en même temps de part et d’autre du cou. La réponse sérologique à la vaccination a été évaluée aux jours 0,21 et 42 par des tests de séroneutralisation. L’administration simultanée des deux vaccins ne produit pas d’effet néfaste et les réponses sérologiques ne différent pas de manière significative de la réponse fournie par l’un des vaccins séparément.

     

Residual foot-and-mouth disease virus antibodies in French cattle and sheep six years after the vaccination ban

A serological survey was carried out on French cattle to establish a reference pattern of residual vaccine antibodies and non-specific reactions against the foot-and-mouth disease virus 6 years after the ban on vaccination and in the absence of any foot-and-mouth disease outbreak. Most of the multi-vaccinated cattle still displayed high titres of antibodies and up to 50% of those which had received a single injection still had antibodies. Non-specific reactors were also recorded among animals born during and after 1991. Most of them displayed low titres close to the threshold. Sheep were also tested and, as for cattle, 4.6% of non-specific reactors were recorded, with titres close to the threshold for two-thirds of them. As part of these animals have been resampled and retested, sera revealed negative confirming that these animals are true non-specific reactors. Serological testing as a mean of FMD control should take these facts into account.     

Ring vaccination against foot-and-mouth disease

The study of the available information, notably after the epizootic of foot-and-mouth disease (FMD) which raged in Western Europe in 2001, shows that, in the current conditions of the international sanitary rules relative to this disease, in a FMD-free country of Western Europe accidentally infected, ring vaccination is a solution which, with regard to preventive slaughter, contains more inconveniences (notably economic) than advantages. The appeal to ring vaccination would be interesting only as far as the international sanitary rules would be modified by taking into account the results expected from the coordinated use of highly purified vaccines and differential research kits (vaccine-linked versus infection-linked antibodies). Propositions are this way made.

Résumé

L'étude des informations disponibles, notamment après l'épizootie de fièvre aphteuse qui a sévi en Europe occidentale en 2001, montre que, dans les conditions actuelles de la réglementation sanitaire internationale relative à cette maladie, dans un pays indemne d'Europe occidentale accidentellement infecté, la vaccination périfocale est une solution qui, par rapport à l'abattage préventif, comporte davantage d'inconvénients (notamment économiques) que d'avantages. Le recours à la vaccination périfocale ne serait intéressant que dans la mesure où la réglementation sanitaire internationale serait modifiée en prenant en compte les résultats attendus de l'emploi coordonné de vaccins hautement purifiés et de coffrets de dépistage différentiel (anticorps post infection/anticorps post vaccinaux). Des propositions sont faites en ce sens.     

Aspects of emergency vaccination against foot-and-mouth disease

Emergency vaccination is one of several measures which may be deployed to control outbreaks of foot-and-mouth disease. It can be a valuable adjunct to the application of the essential zoosanitary controls which must include rapid diagnosis, tracing, movement control and disinfection and which may also include slaughter of infected and in-contact animals and their safe disposal. Criteria which determine the successful application of emergency vaccination include access to vaccine(s) that (i) contain virus strain(s) of sufficient antigenic relatedness to the outbreak strain(s) (ii) are of the required type of vaccine formulation (iii) have acceptable innocuity and potency (iv) have appropriate availability, including quantity and immediacy of supply and (v) meet considerations of cost. Contingency planning should include provision for emergency vaccination and must address the complex decisions of not only when, where, and how to apply vaccine but also its economic consequences. Computer modelling may be a useful aid to cost benefit and decision support systems in this context. Planning must be detailed and regularly reviewed and should ensure, (i) that the legal and financial aspects are catered for (ii) that any contractual supply agreements are in place (iii) that information is collected and its currency maintained on the species, numbers and whereabouts of susceptible livestock (iv) that vaccination teams are formed and trained (v) that the vaccine cold chain is established and maintained (vi) that supplies of vaccination equipment are held in readiness and (vii) that briefing materials are available to inform the various stakeholders on relevant aspects of emergency vaccination. Knowledge concerning the characteristics and performance of emergency vaccines is summarised and areas identified for further research.     

Detection of neutralizing antibodies in calves after single vaccination against foot-and-mouth disease virus type ASIA 1 in the field]

On June 20th 1984 appeared the first FMD-Type ASIA 1 outbreak in Greece. Around the outbreak all susceptible animals were vaccinated with ASIA 1 vaccine produced by IFFA Mereiux. Three weeks after this first vaccination blood samples have been collected and examined for neutralizing antibodies. From 101 examined calves 37 were younger than 6 months, 63 between 6-11 months and one was 12 months old. The titer of the first group was less than 1.2 in 14 and greater than 1.8 in 8 calves. By the second group (63 animals) the titer was less than 1.2 in 28 and greater than 1.8 in 11 calves. The 12 months old calf had a titer of 2.1. Generally the titer only of 59 out of the 101 examined calves was greater than or equal to 1.2 (59%). That means that the vaccine used had a weak immunogenicity.     

Endurance of immunity against foot-and-mouth disease in cattle after three consecutive annual vaccinations

Protection against foot-and-mouth disease (FMD) and ability to transmit FMD virus to susceptible contact animals were studied in cattle vaccinated three times in annual field campaigns with the Dutch trivalent vaccine. Eighty vaccinated cattle and 16 susceptible controls were intranasally exposed to an aerosol containing a homologous FMD challenge virus (O1 BFS, A10 Holland or C1 Detmold) or a heterologous virus (A5 Modena or C1 Modena). The day after exposure, vaccinated cattle were stabled individually with an FMD-susceptible contact. All cattle challenged with an homologous virus strain at one year (20 head), at two years (10 head) and at three years (30 head) after the last vaccination were protected against the development of clinical signs of disease; one, zero and five cattle of these groups, respectively, transmitted virus to their contacts. In each group, approximately two out of three exposed cattle had virus-positive oropharyngeal fluid samples and seroconverted. The amount of virus recovered from probang samples increased with the time since the last vaccination. Mean antibody titres of cattle that had not been vaccinated for three consecutive years did not change significantly over the last two-year period. All 10 cattle challenged with the vaccine strain-related C1 Modena virus were protected against clinical disease, whereas three out of 10 challenged with the heterologous A5 Modena strain virus one year after the last vaccination contracted FMD and transmitted the virus. Five others (four in the C1 group and one in the A5 group) spread the virus to their contacts.(ABSTRACT TRUNCATED AT 250 WORDS)     

4种ELISA检测奶牛O型口蹄疫免疫抗体的比较试验

口蹄疫(FMD)是由口蹄疫病毒引起的以感染偶蹄动物为主的急性、热性、高度传染性疫病,世界动物卫生组织(OIE)将其列为必须报告的动物疫病.我国规定为一类动物疫病.我国奶牛口蹄疫的防控,以免疫接种措施为核心,实行强制免疫政策,要求O型和Asia Ⅰ型疫苗免疫密度必须达100%,通过牛群整体免疫水平的提高来预防口蹄疫的感染和流行[1].     

牛口蹄疫病毒VP2结构蛋白抗体间接ELISA方法的建立

为建立牛口蹄疫(FMD)抗体的检测方法,本研究将口蹄疫病毒(FMDV)的VP2基因,通过pPROEXTM HTb表达载体在大肠杆菌DH5α中表达,获得大小为35ku的重组VP2蛋白(rVP2),western blot证实rVP2可与FMDV5种血清型的牛阳性血清发生特异性反应。以纯化复性的rVP2为抗原建立了FMDVrVP2间接ELISA方法。重复性试验证实批内、批间变异系数均小于10%。特异性交叉试验表明,该抗原不与常见的其他7种牛病阳性血清发生交叉反应。检测非免疫无口蹄疫国家牛阴性血清的特异性为100%;检测感染血清敏感性为97.3%;检测O-AsiaⅠ的二价苗免疫牛血清,与4种商品化试剂盒比较,其符合率分别为69.0%、95.0%、90.4%和86.8%。实验结果表明建立的ELISA方法可以用于口蹄疫感染和免疫抗体检测。     

宁夏固原市肉牛口蹄疫和布鲁氏菌病血清抗体检测与分析

[目的] 为了调查宁夏固原市肉牛口蹄疫和布鲁氏菌病的流行情况,[方法]通过采集74份不同月龄肉牛血清样本,采用酶联免疫吸附试验(ELISA)对2种疫病抗体进行检测和分析。[结果],抗体阳性率由高到低分别为A型口蹄疫(48.65%)、O型口蹄疫(43.24%)、布鲁氏菌病(12.16%)。混合抗体阳性率中主要以O型和A型口蹄疫混合抗体阳性率最高(58.54%)。O型口蹄疫在西吉县的阳性检出率最高(88.24%),彭阳县最低(6.67%);A型口蹄疫在西吉县阳性检出率最高(82.35%),彭阳县最低(26.67%);布鲁氏菌病在原州区阳性检出率最高(15.00%),泾源县和彭阳县未检出。从不同年龄来看,3种疫病均在＞12月龄的肉牛中阳性率最高,分别为O型口蹄疫69.23%、A型口蹄疫76.92%、布鲁氏菌病15.38%。[结论] 固原市各个县区肉牛养殖地区均出现2种病原感染的情况,以O型和A型口蹄疫混合感染为主。在肉母牛养殖过程中,应加强对以上病原的检疫并采取相应的防控措施。     

Stimulation by heterotypic antigens of foot-and-mouth disease virus antibodies in vaccinated cattle

Immunisation of cattle with foot-and-mouth disease virus failed to raise a level of antibody that provides protection against heterotypic challenge. Further the 12S substructure, produced from the 146S particle, was ineffective in providing protection against challenge by homotypic virus. These findings suggest considerable antigenic differences in the virus serotypes and between the virus and its substructure. Inoculation of homologous 12S and heterologous 1246S and 12S antigens into vaccinated cattle, however, revealed antigenic relationship between different serotypes, and between serotypes and their substructures.