Poulvac Bursa Plus is a less attenuated vaccine for use on sites where challenge is severe. In any animal population there will be a small number of individuals which fail to respond fully to vaccination. Successful vaccination depends upon correct storage and administration of the vaccine and the animal's ability to respond. Immune competence can be influenced by genetic factors, intercurrent infection, age, nutritional status, concurrent drug therapy, stress, etc.

Recent field infection or vaccination of the parent flock can stimulate a high antibody titre and consequently a high level of maternally-derived antibody (MDA). Such MDA can interfere with the development of active immunity. The timing of vaccination should be altered in such cases. Determination of gumboro Elisa antibody levels in day old chicks can be made. This allows prediction of the age when maternal antibody levels are sufficiently low to allow effective vaccination and can be made using the "Kouenhoven'' formula (maximum MDA titre 1:500 ELISA units at 14 days by iddex Flockcheck™ Anti-IBD assay kit). Additional information on application and disease control is available from Fort Dodge Animal Health.

Only use as part of a complete gumboro control programme involving hygiene, biosecurity, management, stocking density and disinfection, etc. Overwhelming levels of field virus may overcome vaccinal immunity.

Consult your veterinary surgeon for specific advice on how to vaccinate your birds.