Abstract: The present invention refers to recombinant Newcastle disease viruses (rNDV) having inserted a transcriptional unit foreign to its genome, which codifies for the synthesis of immunomodulatory proteins. These systems provide excellent protection results and significantly reduce the excreted viral load (post-vaccination and post-challenge) in poultry immunized several weeks after being challenged with a velogenic strain of the Newcastle virus. Additionally, said vaccines allow for the protection of poultry against other pathogenic agents during a long time period as they induce an increase of the immunomodulatory proteins level, which results in an enhancement of the immune response of the host and the development of an efficient humoral and cellular response.