Pathogenicity of Bordetella avium under immunosuppression induced by Reticuloendotheliosis virus in specific-pathogen-free chickens

► We model four REV infection which had different immunosuppressive effects. ► We examine changes in pathogenicity of Bordetella avium under the REV immunosuppression model. ► Earlier REV infection could cause severer immunosuppression and enhance B. avium pathogenicity.