Naslov
Evaluation of an intermediate vaccine against infectious bursal disease with elevated virus titre (Gumbokal IM Forte SPF) in laboratory and field conditions

Autori
Čajavec, Stanislav ; Cizelj, Andrej ; Savić, Gordana ; Savić, Vladimir ; Terzić, Krešimir ; Zorman-Rojs, Olga ; Ergotić, Neda ; Markuš-Cizelj, Ljiljana ; Opić, Barbara

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Biotechnology and Immuno-Modulatory Drugs : Programme and Abstracts / Croatian Society of Biotechnology / - Zagreb, 2005, 22-22

ISBN
953-98094-5-2

Skup
4th Croatian Scientific Conference on Biotechnology

Mjesto i datum
Zagreb, Hrvatska, 20.02.2005. - 23.02.2005

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
vaccine; infectious bursal disease; chicken

Sažetak
Infectious bursal disease (IBD), also known as Gumboro disease, is an acute, highly contagious viral disease of young chickens characterized by severe damage of the bursa of Fabricius and immunosupression. The disease is caused by bisegmented double-stranded RNA virus that is classified as a member of the Birnaviridae family. IBD can only be controlled and prevented by proper vaccination and biosecurity. Mild live vaccines dominated until the end of 1980s, when vaccination failures were reported worldwide. After that, vaccine of intermediate virulence strain is introduced, and lately, so called intermediate plus or hot vaccine with virulent vaccinal strain. We chose a new approach in development of vaccines with higher efficacy – intermediate vaccine against IBD with elevated titre. We developed production procedure and registered new lyophilised vaccine against Gumboro disease with 10-fold higher titre of vaccinal virus in relation with previous product. Master seed virus (VMG-91) was grown in SPF chicken embryonated eggs, infected tissue was homogenized and lyophilised with addition of PPGF stabilizer. Virus titre (≥4 log10 TCID50 per dose) is determined on cell culture of chicken fibroblasts. Safety and efficacy were determined in laboratory and field conditions. A ten-fold dose (≥5 log10 TCID50 per chicken) of the vaccine was given to one-day-old as well as 15-day-old specific pathogen free chickens by ocular route. Chickens were observed daily for next 21 days when they were scarified and their bursae were submitted for histological examination. The results reordered in both groups indicated mild to medium severe alterations of the bursa, but also the tendency of their recovery and repopulating with B cells. A commercial flock of 10000 chickens was vaccinated with minimal recommended dose (4 log10 TCID50 per chicken) via drinking water on day 12 of life. Antibody titres of the infectious bursal disease virus were assessed using FlockCheck ELISA kit on day 5, 12, 17, 26 and 40 of life. Significant increase in antibody titres were recorded, reaching relatively high and uniform mean titre at the age of 40 days. Five trials were carried out in field conditions on more than 100000 aniamls. The new vaccine (GUMBOKAL® IM FORTE SPF) against infectious bursal disease is immunogenic, and does not cause any adverse effect in broiler production under field conditions.

Izvorni jezik
Engleski

Znanstvena područja
Veterinarska medicina, Biotehnologija

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