The fastest defense against early Gumboro strains
Infectious bursal disease (IBD) is an immunosuppressive poultry disease. Reported globally, it can infect young broilers from 2-5 weeks of age. Clinical signs include very virulent or subclinical manifestations. Therefore, vaccination in the hatchery is recommended to avoid clinical disease.
Through innovation with a novel frozen IBD immune complex, stopping the Gumboro cycle can be achieved much earlier than before. Nonetheless, vaccinating by subcutaneous or in-ovo routes remains a challenge in many hatcheries worldwide.
A highly contagious immunosuppressive disease
Avibirnaviruses affect the lymphoid tissues in general, and the bursa of Fabricius in particular, which is located dorsally to the birds’ cloaca. The bursa of Fabricius is key for the maturation of the immune system cells, which occurs during the embryonic period and the first 2 weeks of life after hatch.
The B lymphocytes, which play a key role against pathogens, mature in the bursa of Fabricius. They are responsible for the humoral immune response, producing antibodies that recognise and help in the clearance of pathogens.
Difficult to identify clinically with the naked eye due to its various pathotypes (from virulent to subclinical), IBD can have a detrimental impact on viability, feed conversion rate, general growth and uniformity.
In addition, general immunodepression opens the gates to other secondary infections. Thus, the susceptibility of birds to other viruses and co-infections increases.
New strains, new challenges
For many traditional intermediate vaccines, it is very difficult to overcome maternally-derived immunity and colonise the bursa of Fabricius before the wild virus. Moreover, variant and very virulent strains today represent 60-76% of the detected viruses worldwide. This is not taking into consideration reassortant strains, which have been reported, too, since the early 2000s (Figure 1).
Figure 1 – Chronological apparition of new infectious bursal disease virus (IBDV) with new properties. Bringing new challenges and prompting the development of new vaccines.
The virus is composed of a bi-segmented RNA genome (segment A & B), thus when 2 strains co-infect a bird, they might exchange the whole segments and create a new reassortant virus. An example of that is the combination of a classical and a very virulent strain (e.g., A3B1 reassortant genotype detected in Europe).
In addition to this, the virus is very resistant to many disinfectants, with a high persistence in the environment, cycle after cycle.
Gumboro hatchery vaccination
To stop the Gumboro cycle and prevent considerable losses, early protection of birds is strongly recommended – hence the recommendation to do it at the hatchery.
In the hatchery, 2 methods are used to administer IBD vaccines: subcutaneous injection at day-old or in-ovo vaccination at embryonic ages. The objective is to accomplish 100% well-vaccinated chicks developing an appropriate immune response and blocking the bursa from hatch to the end of their life (Figure 2).
When immune complex technology is used, protection happens regardless of the maternal antibody level of each individual chick. On the contrary, when other commercial vaccines are used, maternally-derived antibodies might affect and neutralise them (e.g., drinking water vaccines, naked viruses applied in the hatchery).
These alternative technologies are inefficient to accomplish a 100% vaccination rate, and, in the case of naked vaccine viruses, they might impact the immune system of the chicks in the case of BF colonisation before 14 days of age.
A new frozen solution
To protect chicks successfully against current IBD strains, Ceva has launched Nextmune, a vaccine delivered frozen in liquid nitrogen and produced using an unique technology and formulation (Table).
To bring greater quality and efficiency through vaccine integrity preservation, this new cold chain management process requires expertise and training. These elements are ensured with the Ceva Linilog service.
1 out of 3 broilers is vaccinated against Gumboro by Ceva
Since IBD is mutating and evolving since 1962, poultry vaccine manufacturers must continuously adapt vaccines and solutions against the new threats.
The mission of Nextmune goes beyond immune protection; it blocks the shedding of the IBD virus and limits the selection of new strains. By repeated use of Nextmune, the field virus is finally controlled and rarely detected in the vaccinated flocks. Nonetheless, due to its natural resistance, the IBD virus might remain active in the surrounding environment.
Regular monitoring and laboratory PCR results can be useful to demonstrate IBD virus displacement, stop of the Gumboro cycle and transmission reduction.
Dovac High Speed Line, part of IBD solution control
IBD control does not only come from innovation, but also from an integrated solution composed of immune-complex technology, state-of-the-art machines and close-to-customer services.
But, even the best vaccines might not protect the birds if not applied at the right place and dose. A single not-vaccinated bird might compromise the success of a whole vaccination programme, generally composed of several vaccinations directed to protect against different poultry diseases.
Hence optimising the hatchery day-old chicks’ vaccination plays a key role in the IBD disease control. And that’s why the Dovac Highspeed Line recently came into the market, aiming to replace previous table-like systems (Figure 3).
The goal is to improve efficiency (fewer errors at higher speed) of non-automated hatcheries vaccinating against IBD via subcutaneous injection. The Dovac Highspeed Line workflow optimization allows a 25% increase in vaccination speed while reducing human resources by up to 20%.
Conclusion: IBD stop from start for sustainability
IBD actually ranks among the top 5 most costly poultry diseases. This disease compromises the performance of poultry flocks, leading to carcass heterogeneity and decreasing the economic turnover of the producers.
Since threats are continuously emerging, it is of utmost importance to continue evolving and adapting to the field situation by using proper preventative solutions, ensuring a full protection from the hatchery and securing production sustainability.
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