Protection of Cattle Vaccinated with Inactivated Oil‐Adjuvant IBR‐ Vaccine Against Experimental Infection

Abstract

Summary Vaccination of four to six months old calves with 2 or 5 ml. of inactivated adjuvant IBR vaccines caused production of low titres of neutralizing serum antibodies. Revaccination with the same doses after four weeks resulted in an increase in titer to 1 : 16 — 1 : 512, and in production of measurable amounts of secretory antibodies. After intranasal administration of 4 × 107.6 TCID50 of virulent virus the vaccinated animals responded by a slight increase in nasal secretion containing a low level of virus for 5 to 7 days, but no infectious virus was detected in secretions from animals infected with a dose of 4 × 104 TCID50. Control animals became severely ill after challenge and their nassal secretions contained 107,5 TCID50 of virus / 0.1 ml., and the infection lasted till the 14th day. Local production of interferon was stimulated only by intensive multiplication of the virus on the nasal mucous membranes of the control animals. Immunosuppression by DEXAMETAZON‐Acetate given at a dose of 0.1 mg./kg. of body weight for 6 days eight weeks p. i. resulted in activation of latent infection in both vaccinated and control calves. Zusammenfassung Die Schutzwirkung einer inaktivierten, Öl‐Adjuvans enthaltenden Vakzine gegenüber experimenteller IBR‐Infektion beim Rind Nach Impfung mit 2 bzw. 5 ml einer inaktivierten, Öl‐Adjuvans enthaltenden IBR‐Vakzine entwickelten 4–6 Monate alte Kälber neutralisierende Serum‐Antikörper in geringer Höhe. Revakzinierung nach 4 Wochen erbrachte einen Titeranstieg auf 1 : 16 bis 1 : 512 und die Produktion von sekretorischen Antikörpern im Nasenschleim. Intranasale Belastungsinfektion mit virulentem IBR‐Virus (4 × 107,6 KID50) beantworteten die Impflinge mit geringer Zunahme der Nasensekretion, wobei geringe Virusmengen ausgeschieden wurden. Wurden die Impflinge nur mit 4 × 104 KID50 belastet, war keine Virusausscheidung nachzuweisen. Kontrolltiere erkrankten nach der Testinfektion schwer und anhaltend, ihre Nasensekrete enthielten infektiöses Virus in einer Menge von 107,5 KID50/0,1 ml. Lokale Interferonproduktion in der Nasenschleimhaut wurde nur durch die intensive Virusvermehrung bei den Kontrolltieren angeregt. Eine 8 Wochen nach Testinfektion mittels Dexametason‐Azetat (0,1 mg/kg Körpergewicht täglich über 6 Tage) durchgeführte Immunsuppression aktivierte eine latente Infektion sowohl bei den Impflingen als auch bei den Kontrolltieren. Résumé Action protectrice d'un vaccin inactivé avec adjuvant huileux contre une infection IBR expérimentale chez le bovin Des veaux âgés de 4–6 mois ont développé un faible taux d'anticorps sériques neutralisants après une vaccination avec 2 et 5 ml d'un vaccin IBR inactivé contenant un adjuvant huileux. Une revaccination après 4 semaines provoqua une montée du titre à 1 : 16 jusqu'à 1 : 512 et la production d'anticorps de sécrétion dans la muqueuse nasale. Après une infection intranasale avec un virus IBR virulent (4 × 107,6 KID50), les animaux répondirent avec une faible augmentation de la sécrétion nasale et une faible quantité de virus excrét...

Enhancement Of Pneumo-4 Vaccine Efficacy By Using Of Carbomere As An Adjuvant

“…The potency evaluation of the different prepared formulas of polyvalent viral vaccine in calves represented in table (1,2) revealed that all vaccinated animals developed serum neutralizing antibody titers (SN antibody) expressed as ND reached their peak at first 28 day post inoculation remained stable higher than the minimal acceptable titer of protective level until the end of experiment to the three formulation 1,3and 4. Such data are similar to those obtained by (Bittle, 1968) who recorded that the BVD antibody level 0f 1:8 diluation (ND 0.9) was protective (Zuffa and Feketeova, 1980) and Those authors reported that the minimal acceptable titer of neutralizing antibodies was 1:4 diluation (ND0.6) was protective against IBR, PI-3 and BRS viruses. compared with the control non vaccinated group (group 2) that showed no neutralizing antibody response.…”

Study of immunity induced by the inactivated oil‐adjuvant vaccine after natural infection with the virus of infectious bovine rhinotracheitis (IBR) in cattle

“…application of a large infectious dose. This has confirmed the generally known correlation between the induction of an infection and the size of the infection dose in partially immune cattle (8,28). Under natural conditions, the latent infection state is rarely activated (S), whereby the immunized cattle resist contact infection with small doses of excreted virus.…”

Construction, characterization and immunogenicity of a glycoprotein E negative bovine herpesvirus-1.1 Egyptian strain “Abu-Hammad”

“…Therefore, a double vaccination seemed to induce a better immune response than a single vaccination (Bosch et al, 1996). It has been reported that the minimal immunogenic virus neutralizing antibody titer for IBR (BoHV-1) virus was ≥log 10 0.6 (Zuffa and Feketeova, 1980) or 0.9 (USA Code of Federal Regulation, 1987). All vaccinated calves seroconverted to BoHV-1 gB in the 1 st week post vaccination as detected by gB-based ELISA kit.…”