Newcastle disease (ND) is a highly contagious avian disease that a ects multiple systems in birds and can cause significant mortality in chickens that have not been vaccinated. Prevention and control e orts, including vaccination and strict biosecurity measures, are crucial in industrial poultry production.

Considering the short life cycle of chickens nowadays, generating a proper immune response against diseases as early as possible is of paramount importance for field veterinary practice. The aim of this study was to evaluate if the administration of an inactivated vaccine against ND at di erent doses in day old chickens is able to protect against a challenge infection with a virulent ND virus (vNDV).