Infectious bursal disease virus: new method developed to screen vaccine candidates

Researchers at The Pirbright Institute have developed new tools and techniques to determine the breadth of immune responses produced by vaccines against different variants of infectious bursal disease virus (IBDV). Their study is published in the Journal of Virology.

Eight IBDV genogroups have been identified and there are several variants of IBDV spreading in different parts of the world. Therefore, there is a need to determine whether a vaccine against one strain will produce an immune response against other variants of the virus, and ultimately a need to establish how many different variants a vaccine will protect against.

As it can be difficult to obtain strains from different countries, Pirbright researchers have developed a reverse genetics technique, engineering artificial IBDV strains that mimic IBDV variants from the UK and Europe, USA, Australia, China, and Mexico.

The researchers also developed new tools to test a European vaccine and determine the breadth of immune responses it generated against strains from different countries and continents.

They found that the European vaccine produced strong responses against UK and European strains, but much weaker immune responses against some of variants from other countries.

The researchers say their findings are consistent with field observations and validate the new method, which can be used to screen future vaccine candidates for breadth of neutralizing antibodies and evaluate the antigenic relatedness of different genogroups.

Article: Reddy, V. R. A. P., Nazki, S., Brodrick, A. J., Asfor, A., Urbaniec, J., Morris, Y., Broadbent, A. J. (2022). Evaluating the Breadth of Neutralizing Antibody Responses Elicited by Infectious Bursal Disease Virus Genogroup A1 Strains Using a Novel Chicken B-Cell Rescue System and Neutralization Assay. Journal of Virology, 96(18), e0125522, doi: 10.1128/jvi.01255-22

[SOURCE: The Pirbright Institute]