IBD field challenges are dynamic. Based on management practices, environment, breed, etc., an IBD challenge may change from region-to-region, farm-to-farm and flock-to-flock. When an IBD challenge becomes more robust, mild or intermediate IBD vaccines may no longer protect the birds and performance. In those situations, Bursine Plus, an intermediate-plus vaccine, is an excellent option. Bursine Plus solidly protects against more aggressive IBD challenges.