Expression of chicken interleukin-2 by turkey herpesvirus increases the immune response against Marek's disease virus but fails to increase protection against virulent challenge

As Marek's disease virus continues to evolve towards greater virulence, more efficacious vaccines will be required in the future. We expressed chicken interleukin-2 (IL-2) from a turkey herpesvirus (HVT) in an attempt to increase the efficacy of HVT as a vaccine against Marek's disease. The recombinant IL-2/HVT was safe for in ovo vaccination, although it replicated less in the birds compared with the parent HVT strain. Expression of IL-2 increased the neutralizing antibody response against HVT but did not increase the protection against virulent Marek's disease virus challenge. L'expression de l'interleukine-2 du poulet par l'herpesvirus de la dinde augmente la reponse immunitaire contre le virus de la maladie de Marek mais n'entraine pas une augmentation de la protection vis-a-vis d'une epreuve virulente Du fait que le virus de la maladie de Marek continue a evoluer vers une virulence plus importante, des vaccins plus efficaces seront necessaires dans le futur. L'interleukine-2 (IL-2) du poulet a ete ex...