ABSTRACT
La vacuna antiaftosa utilizada en Sudamérica en las ultimas décadas, presenta una formulación que contiene antígenos inactivados de diferentes cepas virales y un adyuvante oleoso en emulsión primaria del tipo agua en aceite. Esta información resumida y sencilla, en realidad no refleja la complexidad de los procesos de producción y de control de calidad que deben ser cumplidos para la obtención de un producto final que cumpla con la finalidad de proteger a los animales vacunados de la manifestación de la enfermedad. El objetivo de nuestra presentación, es recordar y aclarar algunos puntos que deben ser llevados en consideración por los profesionales que realizan los controles de calidad en los laboratorios oficiales.
Subject(s)
Foot-and-Mouth Disease , Vaccines , Quality ControlABSTRACT
Four groups of ten nine-month-old Nelore heifers were used for this study. Each group received one of four foot-and-mouth disease (FMD) trivalent vaccines for the duration of the experiment. The four vaccine formulations (Normal, 2X, 4X and 8X) differed in 140S content to determine the serological reactivities to FMD virus (FMDV) nonstructural proteins 2C, 3ABC and 3D. Vaccination was by the intramuscular administration of vaccine on day 0, 180 and 360. Bleedings were done at 30 days post vaccination (dpv), 90 dpv, 30 days post revaccination (dpr), 90 dpr, and 30 days post third administration (dprr). There was a general tendency to have higher mean 3D responses with increased vaccine application but not with increased concentration of antigen. With 2C and 3ABC this tendency was not seen, neither with repeated application of vaccine nor with increased antigen concentration. All individual animal observations to 2C and 3ABC remained within three standard deviations of the average observed for naive bovids. Percent of positive (PP) reactions was determined using an ELISA for nonstructural proteins 2C, 3ABC and 3D expressed in baculovirus as previously described. A value of > 25 PP to 2C or 3ABC could be considered as an indication of previous infection or of the presence of viral activity. PP results between 18 and 25 PP suggest viral activity and animals should be retested. Those responses below 15 PP are suggestive of vaccination or naive status. As diagnosis in the laboratory is not divorced from the field epidemiological scene, the intermediate zone between 10 and 20 PP should be considered and acted upon according to the overall zoosanitary situation of that country or region and the purposes of the ongoing FMD control efforts.
Subject(s)
Antibodies, Viral/analysis , Antigens, Viral/immunology , Aphthovirus/immunology , Foot-and-Mouth Disease/prevention & control , Viral Proteins/analysis , Viral Vaccines/immunology , Animals , Antibodies, Viral/biosynthesis , Baculoviridae , Cattle , Diagnosis, Differential , Dose-Response Relationship, Drug , Enzyme-Linked Immunosorbent Assay , Female , Foot-and-Mouth Disease/diagnosis , Foot-and-Mouth Disease/immunology , Vaccination/veterinary , Viral Vaccines/administration & dosage , Viral Vaccines/standardsABSTRACT
Panels of monoclonal antibodies (mAbs) produced against foot-and-mouth disease (FMD) virus types O, A and C were selected for cell culture neutralization titre (NT), mouse protection index (MPI), trypsin sensitivity (TS) and avidity to different epitopes. The selected sets were used to assay the antigen concentration and the fit between FMDV vaccine and challenge strains. It was observed that FMD vaccines protect more than 75% of vaccinated cattle when manufactured with antigens characterized by (1) a high degree of fit with the potency control virus, and (2) mean ELISA 50% titres (T50) > 28 for O, > 18 for A and > 75 for C types, respectively, using the corresponding mAb set.
Subject(s)
Aphthovirus/immunology , Viral Vaccines/immunology , Animals , Antibodies, Monoclonal , Antibodies, Viral , Cattle , Cattle Diseases/prevention & control , Enzyme-Linked Immunosorbent Assay/methods , Foot-and-Mouth Disease/prevention & control , Neutralization Tests , Quality Control , Viral Vaccines/standardsABSTRACT
Foi estudada a supervivência do vírus da febre aftosa tipo O cepa O1 Campos em carcaças de ovinos infectados experimentalmente. Nos ovinos sacrificados em estado febril ás 48, 72 e 96 horas pós-infecçao(HPI) foi detectado vírus antes e após a maturação das carcaças nos músculos Longissimus dorsi (LD) e Semimembranosus (SM) os quais não atingiram pH inferior a 6,0 durante o processo de maturação. Nos ovinos sacrificados ás 120 HPI, 15 e 30 dias pós-infecçao (DPI) não foi detectado vírus antes ou após a maturação das carcaças. Nas carcaças cujos músculos LD e SM ainda continham vírus após a maturação e que foram congeladas a-20§C, isolou-se vírus quando amostras desses músculos foram processadas quatro meses após o congelamento. Foram detectados vírus nos órgãos e gânglios dos ovinos sacrificados ás 48, 72, 96 e 120 HPI. Nos órgãos, os rins apresentaram títulos de vírus que variaram de 10(3,0) a 10(3,7) DI50. Nos gânglios pré-escapulares, submaxilares e amígdalas, os títulos variam de 10(1,8) até 10(4,9) DI50. Nos ovinos abatidos aos 15 e 30 DPI não se detectou vírus em nenhum órgao ou gânglios dos que foram estudados. Em ovinos sadios da mesma raça e idade dos utilizados no experimento e abatidos simultaneamente nos meses da realização do trabalho (verão) o pH das carcaças atingiu valores de 5,96 após 6 horas e 5,36 após 24 horas de maturação. Enfatiza-se a importância do conhecimento epidemiológico da região de onde se originam os ovinos destinados ao abate e o rigor do exame ante-mortem.
Subject(s)
Foot-and-Mouth Disease , Aphthovirus , Sheep , Ganglia , Epidemiologic Studies , Serial PassageABSTRACT
Suspensiones del virus de la fiebre aftosa se trataron a escala industrial con 1 por ciento v/v de triclorotrifluoretano (TTE) o cloroformo para determinar la viabilidad de su uso como agente alternativo para la purificación parcial de antígenos vacunales. En las suspensiones tratadas con cloroformo hubo una disminución media del 50,4 por ciento del contenido proteico total, mientras que en aquellas tratadas con TTE la reducción fue del 33,4 por ciento. Las vacunas formuladas con los antígenos tratados con cualquiera de las soluciones no presentaron diferencias significativas en la inducción de inmunidad cuando se evaluaron por la expectativa porcentual de protección (EPP) en bovinos jóvenes primovacunados. No se observaron inconvenientes en la manipulación del TTE ni aparecieron reacciones posvacunales indeseables.
Suspensions of foot-and-mouth disease virus were treated on an industrial scale with 1% v/v of trichlorotrifluorethane (TTE) or chloroform to determine the viability of TTE as an alternative agent for the partial purification of vaccine antigens. The suspensions treated with chloroform showed an average reduction of 50.4% of the total protein content, while the suspensions treated with TTE showed a reduction of 33.4%. The vaccines formulated with the antigens treated with either of the two solvents did not present significant differences in the induction of immunity when assessed by the expected percentage o protection (EPP) of young cattle vaccinated for the first time. o disadvantages were noted in handling the TTE, nor were there any undersirable postvaccination reactions.
