[Skip to content]

The Pirbright Institute



The Birnaviridae are a family of non-enveloped viruses with capsids of icosahedral symmetry and a bi-segmented genome of double stranded RNA. Several birnaviruses have been identified, infecting birds, insects, and fish. As such, they are a fascinating group of veterinary pathogens and are of major economic importance to both avian and aquatic livestock industries.


Infectious Bursal Disease Virus 

In the Avian Viral Diseases (AVD) Programme, we are focussed on studying Infectious Bursal Disease Virus (IBDV), responsible for Gumboro disease in chickens. The virus is endemic in many parts of the world, infecting B-cells in the Bursa of Fabricius, leading to their destruction by necrosis or apoptosis. Infection can lead to significant morbidity and mortality, and birds that recover may have impaired immune responses, increasing their susceptibility to other infections and reducing their ability to mount effective immune responses in vaccination programmes.


Research Areas

The AVD Programme has a history of conducting world-class research into IBDV pathogenesis, immunology and vaccine development. In order to extend this work, the Birnaviruses group was formed as a separate entity from the Avian Endemic Viruses group in 2014, and is currently lead by Dr Andrew Broadbent, a Research Fellow. Through collaboration both internally with other groups at The Pirbirght Institute, and externally at other institutions, we aim to address the molecular biology, cell biology, and immunology of the host-virus interaction, and develop novel vaccines. Our research objectives are divided into the following areas:

  • Identification and characterisation of host factors responsible for disease pathogenesis      

  • Determination of the viral factors that affect IBDV virulence and their function       

  • Evaluation of novel vaccines against IBDV       


Schematic of IBDV
Schematic of IBDV.
Cultured avian B-cells infected with IBDV.
Cultured avian B-cells infected with IBDV. Courtesy of Dr Andras Donaszi.
Images of a section of the Bursa in an uninfected (control) bird and 48 hours post-infection with IBDV.
Images of a section of the Bursa in an uninfected (control) bird and 48 hours post-infection with IBDV. The panels show B-cells in green (bu1), an epigenetic modification marker in red (5hmC), and merged images with and without the nuclear marker DAPI in blue. Courtesy of Dr Nick Ciccone.