Vaccines for Infectious Bursal Disease Virus
In order to help prevent IBD more effectively, new technologies and next-generation vaccines have been developed and introduced into the market. Creative Biolabs has an advanced vaccine platform that provides reasonable methods to design vaccines without adverse reactions and high efficiency. As a service provider, our goal is to provide the highest level of service with confidentiality and customer support.
Infectious Bursal Disease
Infectious Bursal Disease (IBD) is an acute and highly contagious chicken disease caused by IBD virus (IBDV), which is characterized by virus-induced immunosuppression in young chickens mainly via destruction of antibody-producing B cells in the bursa of Fabricius. The virus rapidly replicates in developing B cells, destroying precursor B cells in the bursa of Fabricius, inducing immunosuppression, which in turn leads to vaccination failure and susceptibility to infection by other microorganisms. Therefore, IBD is considered to be one of the most important viral diseases that threaten the global poultry industry.
Vaccines for Infectious Bursal Disease Virus
Most IBD inactivated vaccines are formulated as water-in-oil emulsions, usually combining several antigens. Inactivated IBD vaccines are also capable of inducing IBDV-specific T cells and inflammatory responses in chickens. It has been reported that inactivated IBD vaccines must have a high or optimized antigen content in order to induce immunity in breeding chickens that help protect offspring from infection by variant IBDV strains. Attenuated live IBDV is often used as a priming vaccine, and inactivated vaccines are most effectively used for priming-boost regimens.
Most commercially available conventional live IBDV vaccines are based on classical virulent strains that mimic infections in target hosts. Live vaccines can replicate and induce cellular and humoral immunity. They do not require an adjuvant and are suitable for large-scale inoculation of chickens, but they may also produce undesirable side effects. In general, live IBDV vaccines used in poultry have been attenuated by serial passage in tissue culture, egg or embryo-derived tissues, in order to maintain the maternal virus-induced immune response while attenuating the ability of vaccine virus causing clinical disease or immunosuppression.
The structural protein VP2 of the IBDV virus is a major protective antigen in which the neutralizing epitope is conformation-dependent and is a potent candidate for subunit vaccines. To date, three vaccines based on the VP2 subunit have been marketed in some countries, where VP2 is expressed in the baculovirus system or in E. coli or in Pichia pastoris. Recombinant subunit vaccines based on expression of VP2 alone may allow the development of DIVA strategies to distinguish between vaccinated flocks and infected flocks.
An immune response to a foreign antigen can be induced by transferring naked DNA encoding the target gene into a host cell. The expression of the antigen in the cell promotes the induction of specific antibodies as well as cytotoxic T cells. Much research has been done on the development of DNA vaccines with different successes to induce an effective immune response in chickens. The cDNA encoding the IBDV polyprotein appears to perform better than the cDNA encoding VP2, and co-administration of IBDV-specific cDNA and interleukin-2 or interleukin-6-encoding DNA increases vaccine efficacy.
- Immune Complex Vaccines
The new concept of vaccines is to build immune complex vaccines. These vaccines consist of a mixture of an amount of IBDV-specific antibody and an infectious IBD vaccine virus obtained from hyperimmune chicken serum. Their main advantage is that they are suitable for in ovo vaccination on the 18th day of commercial eggbeater incubation. Moreover, these vaccines are effective in the presence of maternal antibodies. Thus, a more automated and systematic administration process is permitted by drinking water or eye drops.
In addition to the above common vaccines, Creative Biolabs also provide the development and production of new vaccines such as live viral vector vaccines and genetically engineered live IBDV vaccines. If you want to know more information, please feel free to contact us.
Reference
- Müller, H, et al. (2012). Current status of vaccines against infectious bursal disease. Avian Pathology. 41(2):133-139.
All of our products can only be used for research purposes. These vaccine ingredients CANNOT be used directly on humans or animals.
