IMMUNOGENIC RESPONSE WITH EFFICACY OF CERTAIN GUMBORO VACCINES IN BROILER

Abstract

The research work was carried out to determine the immunogenic response with efficacy of six commercial Gumboro, vaccines (Nobilis® Gumboro D78 and Nobilis® Gumboro 228E, Intervet, The Netherlands; Bur-706®, Merial, France; TAD Gumboro vac® and TAD Gumboro vac forte®, Lohmann Animal Health, Germany; BursaplexTM, Merial Select, Inc. Gainesville, USA) under experimental condition in broiler chickens during the period from November 2002 to May 2003. The chickens of two groups were vaccinated with Nobilis® Gumboro D78 and Nobilis® Gumboro 228E at 14 days of age with a booster dose at 21 days of age and were challenged at 40 days of age with vvIBDV. TAD Gumboro vac® and TAD Gumboro vac forte® were inoculated into the two groups of chickens at 14 and 28 days of age and the chickens were challenged at 35 days of age with vvIBDV. Bur-706® vaccine was given to the chickens of another group at one-day-old and 14 days of age and the chickens were challenged at 28 days of age. One group of chickens was vaccinated with Bursaplex vaccine at 1-day-old with no booster dose and was challenged at 21 days of age. The percentage of protection in birds receiving Nobilis® Gumboro D78 and Nobilis® Gumboro 228E vaccines by intraocular route was 92.30 and 96.29 respectively, whereas the percentages of protection in birds receiving TAD Gumboro vac®, TAD Gumboro, vac forte® and Bur-706® vaccines were 95.65, 100 and 95.83 respectively. BursaplxTM provided 100% protection against challenge with vvIBDV. Chickens vaccinated with Nobilis® Gumboro D78, Nobilis® Gumboro 228E, TAD Gumboro vac®, and Bur-706®, showed significant (p < 0.05, p < 0.01) decrease in ELISA antibody titre up to the day of challenge infection. BursaplexTM vaccinated group also showed significant decrease in ELISA antibody titre by 7 days (p < 0.05) and by 14 and 21 days (p < 0.01) after primary vaccination. In case of TAD Gumboro vac forte®, 7 days (839 ± 219.34) and 14 days (258 ± 44.80) after primary vaccination, the ELISA antibody titre significantly (p < 0.01) decreased but 7 days after booster vaccination, the ELISA antibody titre significantly (p < 0.01) increased (1299 ± 37.51). All the control sera revealed significant (p < 0.01) decrease of ELISA antibody titre up to day of challenge infection. There was an insignificant increase in ELISA antibody titre 7 days after booster vaccination in case of unvaccinated control groups for TAD Gumboro vac® and TAD Gumboro vac forte® only. Nobilis® Gumboro D78, TAD Gumboro vac® and Bur-706® vaccinated groups revealed significant (p < 0.01) increase of ELISA antibody titre 7 days post-challenge while Nobilis® Gumboro 228E and BursaplexTM vaccinated groups showed significant (p < 0.05) increase of antibody titre after 7 days of challenge. Insignificant increase of antibody titre was recorded in TAD Gumboro vac forte® vaccinated group. It may be concluded that TAD Gumboro vac forte® (intermediate plus) and BursaplexTM (Merial Select, Inc. Gainesville, USA) can be used to immunize the broiler birds sufficiently against IBD. However, it is necessary to estimate the optimum vaccination timing, i.e., to determine when maternal antibodies in chicks will decline to levels that the vaccines can overcome.