07.02.2014

The Georgia 2008 (GA08) strain of infectious bronchitis virus was first isolated in the winter of 2007 in a flock of 47-day-old broilers in Northeast Georgia. Flocks demonstrated mild respiratory changes but the economic loss arose from condemnation as a result of septicemia and airsacculitis. The variant strain of infectious bronchitis was isolated and it was demonstrated that conventional vaccination using Arkansas and O72 strains failed to provide protection. Cross neutralization studies with GA 08 and Mass, Conn, Del 072, and Ark revealed little neutralization.
In response to the financial losses, an experimental autogenous GA08 vaccine was applied by one integrator in Georgia, combined with Ark. and GA.98 for both hatchery and field booster vaccination. This approach was successful and continued for two winter seasons. While investigations were continuing, the variant GA08 continued to spread from Georgia to Alabama and then to Tennessee and emerged as a serious problem in the spring of 2012. High condemnation was recorded from flocks which were not overtly affected by IB during the grow-out period. The condition was even more evident during the spring of 2013 with isolations from Georgia, Alabama, Tennessee and Kentucky.
Now Zoetis has obtained a conditional license from the U.S. Department of Agriculture (USDA) to market  the first commercially available vaccine to control IB infection caused by the Georgia 08 variant in chickens. The vaccine is now available in Alabama, Florida, Georgia, Kentucky and Tennessee. The USDA agreed to issue a conditional license (Efficacy and potency test studies are in progress) because the modified-live vaccine fills a special need, has been shown to be safe and has demonstrated a “reasonable expectation of efficacy” against the target pathogen. Zoetis was able to achieve this goal in only seven months, thanks to the strong support of industry and the USDA.