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Infectious Bursal (Gumboro) Disease*

One of the most common viral infections in chickens, infectious bursal disease (IBD), also known as Gumboro disease, is caused by the IBD virus, which destroys B lymphocytes in the bursa of Fabricius, a specialized organ of birds' immune systems. Found worldwide, IBD mainly affects younger chickens up to 6 weeks old, whose bursas are still under development. It can cause not only a variety of debilitating clinical signs, but also an underlying immunosuppression that leads to poor growth and performance, with significant economic impact on the poultry industry.


Disease Management Approaches

The IBD virus is highly contagious to other chickens via their feces, and once established can be very difficult to eradicate, especially in farm and production settings. So while good hygiene practices play a role, vaccination is most important in aiding in disease prevention and control,* especially as IBD cannot be treated post-infection.

Viral strain diversity falls into three broad categories based on virulence, with varying clinical signs, mortality rates, and degree of immunosuppression. The disease has a sub-clinical form that, while lacking outward signs, can depress growth and performance, increase susceptibility to other pathogens, and reduce uptake of vaccines for other diseases. So IBD vaccination may be advisable even in the absence of obvious field challenge.

Because of the particular vulnerability of the developing bursa in younger birds, early protection is most important, but can also present challenges. Newly hatched chicks inherit maternal antibodies against IBD that decline as vaccine-induced immunity develops but while still present can interfere with some types of vaccines. Historically, calculating appropriate timing of IBD vaccination with respect to maternal antibody levels could be challenging and laborious.

In more recent years, new technologies such as vector vaccines have enabled simpler vaccination protocols developed around standardized hatchery administration. However, maternal antibodies still play an important role in disease protection, so breeder flocks may be revaccinated, often with live and/or inactivated vaccines, in order to promote passing of immunity to progeny.


Merial’s Solutions**

Damage to the bursa in a chicken's early weeks sets it up for immunosuppression. At Merial our approach to IBD protection is focused on preserving bursal integrity, which means prioritizing early vaccination at the hatchery. But to accommodate all customer needs, we offer IBD products (including the three generations of IBD live vaccines)** for both hatchery and field administration:


  • VAXXITEK® HVT + IBD, our globally marketed,*** two-in-one vector vaccine for hatchery administration that uses the HVT virus as a vector, thus also protecting against Marek's disease (serotype 3 )
  • BDA BLEN/GALLIVAC BDA™, a freeze-dried live, intermediate plus virus of IBD mixed with IBD antiserum (marketed in some countries**) for hatchery administration
  • GALLIMUNE, our multi-region** line of inactivated vaccines, many of which are combination products that include IBD along with other diseases
  • A selection of other live frozen and freeze-dried vaccines, including Merial Inc. (U.S.) vaccines, for various IBD strains


VAXXITEK HVT + IBD as our flagship product reflects our immune foundation approach: vaccinate early, at the hatchery, against the most serious immunosuppressive diseases that can be controlled by vaccination to optimize poultry health and productivity. Yet we recognize that our diverse customer base needs equally diversified options. Brand and product availability vary across markets, but we are always evolving our offerings to address new challenges and changing epidemiologic conditions.

Our customer solutions also include the expertise of our Veterinary Services teams, who bring deep epidemiologic knowledge and diagnostic tools for assessing field challenge, flock immune status, and other factors that contribute to a customized vaccination program for IBD. And Merial's Vaccination Technologies & Services (VTS) group offers on-site audits and consulting for a smooth transition to hatchery vaccination, as well as innovative equipment, training, and support.


More About Infectious Bursal (Gumboro) Disease*

IBD is also called Gumboro disease, after the town of Gumboro, Delaware, U.S., where it was discovered in 1962. It is widely found in chickens all over the world. Vaccination has helped control the disease for many years, but new IBD strains are frequently emerging. In the late 1980s a very virulent strain emerged in vaccinated flocks in Europe and spread rapidly across the globe, while in North America a more sub-clinical variant form arose.

The clinical and sub-clinical manifestations vary depending largely on virus strain; these can be grouped into three categories:





  • Bursal inflammation / lesions
  • Listlessness and wasting
  • Muscle hemorrhaging
  • Moderate mortality rates
  • Immunosuppression


Primarily sub-clinical, with few external signs but inwardly showing bursal atrophy and underlying immunosuppression

Very virulent

Severe clinical signs including:

  • Bursal and muscle hemorrhaging
  • Listlessness, wasting, and poor overall appearance
  • Extreme bursal atrophy
  • High mortality rates
  • Severe immunosuppression (in birds that do survive)


Even in the absence of external clinical signs, the immunosuppressive effects of IBD can cause poor growth and performance, leading to major economic loss:

  • Reduced broiler carcass quality and lack of uniformity increases production costs
  • Poor uniformity in pullet bodyweight, which leads to decreased egg production in layers, whose genetics have been found to be particularly susceptible to the disease
  • Birds are more prone to secondary infections and less responsive to other vaccines, leading to increased medication costs


*Merial produces and markets several vaccines against infectious bursal (Gumboro) disease. However, be aware that NOT all aspects of the disease mentioned on this page are addressed by a vaccine. Always consult the product label for exact vaccine indications.

**Many of Merial’s avian vaccines are only marketed and available in certain countries, sometimes under different trade names. Speak to your Merial representative or contact us to find out what’s available in your region.

***A vaccine product sold under the VAXXITEK® HVT + IBD trade name is available in more than 75 countries worldwide.




To find out exactly which Merial avian products and vaccination equipment options are available in your region, talk to your Merial representative or contact us now.

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